PERCEPTION

There is much more to fighting than the physical techniques.  A powerful and fast blow is useless if the target is not there when it arrives.  A powerful and fast combination will achieve nothing if every blow is blocked, or if the opponent takes advantage of openings created by the movements of the combination.  Likewise, your attacks will become more precise and effective if you can anticipate your opponent’s movements and attacks, or feel his/her momentary lack of attention.
In order to strike your opponent in the right place and at the right time, and to avoid providing the information for you opponent to do the same, you must become aware of all aspects of the fight; your opponent, yourself, and the interaction between you.
Discussion in this area may seem somewhat esoteric and vague.  I admit that this is the case.  I use the concept of Chi when discussing perception.  I can’t define Chi or show it to you, but it is what I call the feeling that allows me to perceive movement, intent, threat, weakness and opportunity.  Unfortunately, there is no easy way to teach a student how to use Chi.  The best that I can do is provide some guidance and some techniques that may help the student to encounter Chi.  From there, he/she may be able, with practice, to learn to use it in a fight.  This paper is an attempt to provide that guidance.

Mental

It is important to be totally within yourself to fight.  If you are moved by outside forces, you lose control to the extent that they move you.  If you commit mentally to a direction, to an action, or to inaction, it can be as detrimental as a bad physical movement.  For instance, if you are expecting to hit your opponent in the leg while blocking his/her head blow, you are likely to be completely foiled if he/she is successful at blocking your blow, while striking for your leg instead of your head.
You should strive to be totally ready, but not ready for any specific thing.  In some arts, this is called “no-mind”.  In that way you will not have to stop committing to a mental pattern before you do what you need to do.  Also, if you are not watching for a particular motion or situation, you will notice others that occur.
Think of your mental approach to fighting as a three-position switch.  The three positions are forward, reverse, and neutral.  If you are in reverse, mentally, and you have to change to forward, you must first go back to neutral before going forward.  This can cause a fatal hesitation. 
This is a very simple analogy.  During a fight there are numerous ways in which you can commit or anticipate.  The analogy still holds, though.  During a fight, the switch has a multitude of settings, not just three.  There is still a neutral, though, and that is where you should stay, unless actively doing something.

Flow

Try to make the whole fight a single entity, so that any movement is noticed and acted upon.  Act as if the fight is a dance, where your partner's actions influence yours, and vise-versa.  Waltzing is a good analogy.  In this dance, pressure from your partner’s hands indicates directions of movement.  One movement leads to a set of other movements, so a degree of anticipation is quite possible. 
Fighting is like waltzing three feet apart.  The movements of your opponent's body, sword and shield act like the hands of your dance partner to push or pull you.  If you learn to perceive the flow of the fight, you will begin to anticipate your opponent’s movements, and notice openings before they occur.
Dressage is a good example of where you want to go with this concept.  At the highest level of this art, the communication between horse and rider is so sensitive that the rider does not use overt movements to control the horse.  He/she simply thinks about what he/she wants the horse to do.
Try to get to the point where you can feel a swing push you out of the way, or pull your shield into it.  Try to get to the point where the motions of your opponent's body draw your sword to the openings towards which these motions lead.

Tells

Well over half of the information in normal discourse is through body language.  It is likely that we are all adept at receiving and processing the information presented by this medium.  During combat, no information is passed by words spoken, tone of voice, or facial expression.  So we are left with body language.
Advance information of your intentions, that you supply to your opponent, are called “telegraphs”, or “tells”, as in “I’ll send you a telegraph to let you know when I’m going to swing.”  There are a number of types of cues that can serve as Tells.
It is important to pay attention the motions in your opponent's actions.  Motions can include gross movements, like a molinet, or subtle things, such as a small rotation of the sword hand before a swing.  They can include obvious movements, such as leaning into each step of a forward walk, or things less obvious, such as a slight weight shift that indicates a step will be taken with the back foot.
Any of these can provide the evidence to tell you what your opponent’s next move will be, thereby allowing you to start your defense or counter-attack before your opponent actually starts to perform the attack itself.
It is also important to pay attention to the patterns in your opponent’s movement or lack of movement.  These include the habit of standing motionless too long, walking in a repeated pattern of steps, waving the sword up and down, swinging the shoulders from side to side, or attacking with the same sequence of blows, time after time.
Any of these can provide very usable information about timing and intent.
In the case where you opponent is waving his sword up and down, it is quite possible to time the points in the pattern of movement where it is impossible to swing the sword forward.  In this example, one such point is halfway through the downward movement of the blade.
In the case where an opponent has not moved for too long, subtler cues, such as a slight slumping of the shoulders, indicate that the intent has shifted momentarily to not moving, rather than readiness to attack or defend.  A quick attack at this moment can often succeed.

Preparation

In the martial arts, as well as in many sports, after the physical techniques have been mastered, the game becomes mostly mental.  The perception and anticipation that is so important in fighting cannot be achieved unless the mind is centered, as well as the body.  I have known several fighters who did not perform up to their potential, despite possessing remarkable physical gifts and being technically adept, because they never managed to master the mental game.  They would succumb to "tourney jitters", or "psych themselves out".
The state of mind that I prefer to employ is a calm, but very intense, attentiveness.  By calm, I do not mean relaxed.  What I mean is being free of concerns and distractions, while being focused on the business at hand.  I try to turn myself into a very sensitive receptor of cues, being ready to instantly react properly to any stimulus. 
You need a general focus on the fight, to include yourself, your opponent, and the relationship between you.  It should be as if you are waltzing, and your opponent is your partner. You should not be expecting anything specific to happen, but rather be ready to react to anything.  This sounds a bit like the recipe for enlightenment.  I suppose it is a start in that direction.  Similarly, it’s not as easy as it sounds.
There are several ways to prepare for this.  The method I find most effective for me is to practice the mental game in other settings, where the pressure of a tournament is not present.  The main venue for this is on the practice field, and usually during exercises, rather than actual sparring. 
However, it is also important to be able to bring this mental preparedness to the tourney field.  A useful method in helping with the translation is to include some events in practice that are also present in tourneys.  When one of these events occur in the tourney setting, it will help to call up the state of mind you worked with in practice.

Learning Techniques

The following are some techniques that I’ve found useful with this aspect of preparation, and others discussed in this paper.  However, you will get out of them what you put in.  There is no free lunch.  You have to practice them, too.

Saluting
One technique that I have found very useful to help with centering and calming is to design a sort of physical mantra, or routine, which will help to do this, and get you into the right state of mind of mind.  I use the salute to do this.

1. Use a standard salute every time you engage in a practice exercise that involves a partner, or even a pell.  This will associate the act of saluting with the relaxed, unpressured calm intensity that you should employ in practice.  When this same salute is used in a tourney setting, it will act as a cue for you to get in that same frame of mind.
2. What I do is to first raise my sword in a salute, and when I bring it down towards my stomach, I center myself.  Then, I make wide, “gathering” movements with my sword and shield to bring them into position.  I imagine my shield pulling my opponent into me, and my sword pulling me towards my opponent.  As everything comes together into the dance, I shift my weight slightly to the balls of my feet, to avoid "planting".

As you get accustomed to using the ritual, you can abbreviate it more and more, until you can just use a mental command to move yourself into no-mind, or to re-focus and get back into it, once you've lost it.  This is the result of practice.

Slow Work
Structured, rhythmic slow work is useful in helping you to get into the flow of fights.  This will help you to anticipate both attacks and opportunities.  The rhythm and slow speed of the action takes out much of the anxiety and surprise that can be present in a full-speed fight, allowing you to focus your practice on some of the mental aspects.  It can also be used as a method of integrating techniques into actual fighting.  This is why it is necessary to be very structured, and abide by the rules.  If you are moving through your slow work as a moving meditation, you can be abruptly pulled out of this by a partner who speeds up, or moves the sword in a way that would be impossible in full-speed fighting.
Again, this should be a no-pressure environment, with the rhythm helping you get into the practice of "feeling" what will come next, and the slow speed giving you time to think about things.  It is similar to waltzing, as I described above.  The movements of your partner give you cues as to where it is appropriate for you to move.  The better you feel the flow of the dance; the better you will be able to react properly and effectively.
If you don’t have a partner at all of your practice sessions, you can treat a pell as if it was one.  Use a lot of combinations involving movement.  Block and strike towards different points.
A more complete treatment is in the Training Exercises paper, and in my on-line manual.

Sticky Hands
There is an exercise taught in many Asian striking arts called “sticky hands”.  The principle involved is useful in almost any art or sport where opponents are contesting.  It teaches the student not to over-commit, and to take advantage of the over-commitment of his/her opponent.
For instance, if you can get your opponent to strongly commit to blocking a leg blow, and the actual target is the head, you will have a better chance to land the blow than if your opponent was ready to block any target.
I use this extensively in my great weapon techniques using the weapons instead of hands and wrists.  However, the concept applies to all fighting, including group combat and full battles, where the threats need not even require contact.
The exercise goes as follows:

1. The two exercise partners stand facing one another, about 18 to 20 inches apart – so that by easily extending an arm, not fully, they can touch their partner’s chest with their palm.
2. Each partner in the exercise starts with one arm extended about eight to ten inches, with the palm forward, and the fingers pointing up.  The wrist of the extended hand should be about four inches above that elbow.
3. Choose one of the partners to be on offense, and the other on defense.
4. The goal of the partner on offense is to touch the palm of his/her hand to the center of their partner’s chest.
5. The goal of the partner on defense is to prevent this by gently pushing their partner’s arm sideways, up or down, away from the target.
1. Generally, wrists and the sides of the hands come in contact, not the palms.
2. This is not a contest of speed.  Everything proceeds at normal speed – not artificially slowly, but not fast at all.  Nor is it a contest of force.
3. The hands or wrists should remain in contact during the exercise.

The strategy for the partner on offense is to cause the defender to commit to a push that is harder than necessary, then to reverse the attack to the opposite direction – something like a disengage in fencing, but with the hands remaining in contact.
The strategy for the defender is to use the precise amount of force in the proper direction to defeat an attack, while remaining in position to defend against the next.  One effective method a defender can use is to push back on diagonals towards his/her opponent’s shoulders, rather than directly sideways.
Try doing it with your eyes closed.

Visualization

Visualization can be very useful, both in learning physical techniques, and in learning the perceptual aspects of the mental game.  It’s sort of a "fake it 'till you make it" method, where you imagine things are visual and tactile, then behave as if they are.  Eventually, you can start to perceive things to a degree, as if they were.  
I do things like imagining that the air is thick and glowing, like a thick fog, and that a movement by my opponent will cause me to feel a pull or a push, transmitted through this thick medium.
I also imagine that I can spread a web of fine filaments between my opponent and myself.  When he/she moves, the web either pulls or goes slack, giving me a warning, and providing information as to the direction of the movement. 
When I use this as an exercise for students, I have one student hold a sword vertically, and the student doing the visualization to stand in front of him/her, and grasp the sword with one hand.  Then I have the student release the hand, and back up two or three steps.  As the sword is released, he/she should visualize the filaments coming out of their fingers, remaining attached to the sword.  As he/she moves back, imagine and try to feel the filaments stretching, and becoming tight. 
Once this is done, have the student with the sword pull it slowly away from the visualizing student.   He/she should try to feel the filaments stretch further.  Then move the sword forward.  The visualizing student should try to feel the filaments relax. 
You can also use visualization to work on yourself.  If you're feeling tense, imagine that a color or a feeling will wash over you, starting at one point, and moving all over your body, bringing calmness or focus.  I usually start at my forehead.  When the color/feeling has passed, that part of you will be calm/ready.