As a former high school all state QB, the one drill I remember the most and believe helped me more then any other drill I ever did was... When passing the ball it is a key factor on how the QB drops back. A pass play is useless if the QB trips over the center, or his on feet. Lay out bricks about a foot and a half apart. Depending on the step of the drop use... 3 step drop, 2 bricks, 5 step drop 3 bricks. Have the QB line up with the ball in his hands as if the center was there to snap him the ball... Have the QB lift his back foot first up and over the first break, and hope his front foot into it at the same time he is moving his back foot into the next, until both of his feet have gotten behing the last brick. He will learn to lift his feet high enough in the air and the correct distances... After tripping over the bricks and falling down enough times he will learn to lift his feet. He will become faster and faster at it and really improve the time he has to throw the ball while in the pocket.