Basketball is a team game, but creating your own shot is an INVALUABLE skill to have in your arsenal and extremely useful no matter what position you play. A player that requires a teammate to set them up or a screen to get an opening to score, is severely limited and less effective.
Its players that create their own shot that opposing teams really have to worry about containing. So now the question comes up: How do you create your own shot? Well, athleticism and speed can play a big part in this, but there are techniques and skills that can be learned as well.
One skill is the crossover dribble. If you can beat your defender off the dribble, you can create your own shot. However, this requires that you're a good dribbler.
Think about it like this: you want to CREATE SPACE between you and the defender. If he or she is too close to you, then you won't be able to get a clean look at the basket.
Watch this video from the TNT fundamentals series, featuring NBA player Sam Cassell, the master of the mid-range game:
Did you watch it? Now, let's review what he talked about. When you're driving, lower your shoulder, bump the defender, which creates space, step back, and pull up for the jumper. Don't bump the defender so hard that they fall; this can be called a charge. You just want a "slight" bump that disrupts the defender's momentum.
Another thing Sam talks about is the hard dribble. You dribble hard in one direction so that the defender will MOVE BACK. Now think about it, the defender can't jump at you and block your shot if he's moving backwards. Immediately after the hard dribble, step back, get set, take the shot.