If you are a good team, your offense is born on the defensive end.
Don't be in a hurry to change during the season.
Put your two best players away from the ball and bring it back to them.
Only run special plays for special players; find plays that fit your players.
You have to learn things in every game because you are not going to be able to practice two-and-a-half to three hours (during the season), so the games have to be the ultimate learning experience.
Quickness more than anything else should determine your amount of pressure on the ball.