1. Always line up with your feet well underneath you so that you are ready to fight pressure from any direction. The only thing that over rides the first sentence is; pass only responsibility, this can elongate a defensive lineman's stance.
2. Always concentrate on the man nearest you, for he is the man who can block you first.
3. Never raise up to look for the ball carrier, for the blocker will tell you where the ball is going.
4. Always keep your back parallel with the ground and you then become very difficult to block.
5. Do not go to the ground, but if you do so, get back up quickly. A football player's ability can be equated by the amount of time he spends on the ground.
6. In defeating the trap, first, know who is going to trap you. Secondly, use your head to get to an "anti-trap" position. As you turn to play the trap, keep your head on your side of the L.O.S. and you will never be trapped. If you get to much penetration, then spin back inside.
7. Never allow a blocker to get into your legs, for if he does you will go down, and on pass this is a cardinal sin.
Courtesy of: Jerry Campbell