It's Not Only How To, It's Who To And When

2) Turning away and taking your eyes off the defense as you drop back. This is a bad mistake because it means you will waste precious time by not being able to start analyzing the defensive patterns until you have finished dropping back and are set up.

3) Trying to throw while your weight is still back on the right foot. This usually happens when a quarterback has been rattled by a pass rush. You simply must learn where your blockers will set up the pocket and step forward into it when you throw.

4) Twisting the wrist clockwise at the release. This error usually results in the palm facing upward on the follow-through and a pass that looks like a butterfly in flight.

AND SO ...
The art of playing quarterback and throwing a football are fundamentals that can be mastered through practice. The art of thinking, of being able to plan a few plays ahead, on the other hand, comes only through long study of opponents' defensive tendencies. The difference between winning and losing is the consistency, both in theory and in application, with which you do your job.