Balance.
Stand with your feet shoulder width apart and distribute your weight equally between them. Square your shoulders and feet to the hoop and bend your knees. This is where your stability and strength will come from — many first-time ballers think that their power is in the arms and end up chucking the ball at the basket. It's a dead giveaway that you don't know what you're doing. Instead concentrate on bending your knees and getting your power from your legs.
Elbow.
Your elbow should be at a 90-degree angle pointed toward the basket, so your forearm is perpendicular to the floor.
Eyes.
Keep your eyes on the hoop, not on the ball. Focus your gaze on the front of the rim and see the ball going into the basket.
Follow-through.
When your shot is over, keep your hand in the air. It should look as if you're trying to dip your fingers into the basket. This will ensure that the ball goes where you want it to. If you are shooting and the ball is going off to the side, check out your hand — most likely, it's pointing away from the basket.
The most important thing in foul shooting is routine. Find a drill that works for you — whether it be three dribbles or none — and stick to it every time. Just don't try anything fancy like spinning the ball on your fingertip or throwing it in the air. Unless you are a Harlem Globetrotter — and if you're reading this, I assume you're not — you will look like an idiot. Keep it simple, and don't stray from your routine. In foul shooting, repetition is a good thing.