The wonderful skill we call setting has haunted some with a loathsome curse. The words "I can't set", "My hands are like meat hooks", or "I'm a hitter not a setter" have been heard in gyms since this game started. Subsequently, setting is a domain some refuse to enter for fear of failure, being ridiculed, or simply fear of a disappointing moment of poor execution. What is the best thing you can do to learn how to set? Answer: repetition.
Let's start with the basics.
HAND POSITION
Put your hands above your head and put your index fingers and your thumbs together. Now you should be looking through a "window" that these fingers make. Position your hands so that if a ball small enough to go through your "window" went through the center of it, the ball would hit you right between the eyes. Now put your other fingers together (keeping them straight and only touching at the finger tips--down to the first knuckle). As you pull your fingers apart, you will feel as though a ball would fit in between your hands perfectly as they become a certain distance apart. This distance will be the position you will start your hands in before you contact the ball. If you are having trouble finding this position, grab a ball and decide that way.
HAND ACTION
The ball should only contact your fingers and never the palm of your hand. The points of contact on your fingers when setting the ball should be similar to the contact points when you had your hands together earlier. The ball should contact your thumbs and first two fingers with an equal amount of force, while your last two fingers on both hands may contact the ball sometimes (for extra control), but with less force. Therefore, do not pull your last two fingers back out of the way--keep them there for those sets that will require more control on the release.
The real "action" takes place in your wrists. The more flexible your wrists are and the stronger and faster your forearm muscles are, the better setter you will be. Your elbows should be slightly bent at the time of contact with the ball (about the angle you bend your arms to type) and your hands should be in the ready position we discussed earlier as the ball contacts your fingers. You should be able to lay on your back and hold the ball in your hands (which are in the ready position) and move only your wrists to throw the ball a few inches into the air--of course, you'll have to adjust the angle of your arms so that the ball won't shoot behind you, but will go straight up in the air and land back in your hands.
Throw the ball with your wrists only, catching the ball back in your hands and pausing to make sure that the ball lands softly and your hands are in the correct position at the time of contact. In order to allow the ball to land softly, you must time the contact in such a way as to retract your wrists at the same speed the ball is coming--kind of like a trampoline will softly catch you as you land. After you are skilled at the down portion of this "trampoline" movement, we can stop pausing for quite as long before you throw the ball back into the air. Work at this only using wrist movements (don't use your arms yet). Keep doing this drill until there is no slapping sound when the ball hits your hands. After you have the timing down for this wrist movement, we can move on to the arm action.
ARM ACTION
While still laying on your back (don't worry, we'll eventually stand up), start the movements described earlier--throw the ball with only your wrists and "trampoline" the ball back into the air softly. The arm action starts as the wrists move to throw the ball back into the air--not before this moment. Don't make the mistake of cushioning the ball with your wrists and arms--this will constitute a "throw" in the volleyball world. As your push with your wrists to release the ball, extend your arms simultaneously. As you do this, the ball will go much higher requiring you to become even better at cushioning the ball as it lands in your hands (which, of course, are in ready position). As your timing gets better, your action of hands, wrists, and arms become smoother and more controlled. I still do this drill to improve my touch on the ball.
Now it's time to get on your feet and use your skills. Always try and set with your right foot slightly in front of your left, always facing the left side of the court, and, if possible, at the time of your release, have your shoulders square to your target. Sometimes you will be running around sprinting for balls, but if you will try and set up (even if it's at the last second), your sets will begin to be more consistent and your team will be more successful. As you release the ball, you should be shifting your weight from your left to right foot. It is a bad idea to be setting with your weight on your back foot--you'll have less control and will tend to "underset" the ball.
TACTICS
What goes through a setter's mind as she runs the offense? What should go through their mind? What can you do to prepare for the mental challenges faced by the setting position? There is definitely a difference between the personalities of the setter (a good one anyway) and the other players on the team. Many times you'll see the setter watching matches at a tournament while the rest of the team is talking about what they did last weekend. You'll notice that the setter keeps the same basic temperament throughout the match, while her teammates go up and down. You'll notice that the setter tends to be supportive of his hitters and other teammates even when they make errors at crucial times in a match. You'll never see the setter discouraging a player, or punching the pole, or showing an extreme outburst of emotion. At most, and I see this a lot, the setter will let out a yell that lasts for a second and then turns to the hitters and gives them their calls. A setter should be the most emotionally and mentally stable person on the team. The setter should be a great leader. It should be someone who is not afraid to take control. The setter should not be afraid to give orders. The setter should have a deep understanding of the game, and understand her teammates abilities, responsibilities, and their weaknesses. A great setter always feels comfortable taking the blame for all failed attacks. A great setter is not afraid to take chances, challenge her hitters, and set the ball to the hardest location relative to their position. The best setter is the one that knows her team is going to win the match and is willing to do whatever is necessary in order to reach game point.
Although the setter's job description is lengthy, it is probably the most rewarding. A setter can be 5'5" and still be very effective. There are many advantages of being a 6'0" setter, but you'll never be great without the mental and emotional stability outlined above.