Reading The Defense
Step 1. Come out in I Form Normal (or any formation with WR's on the outside of the field)
Step 2. Audible up to SG Bunch TE (or any compressed set IE: snugs/bunch)
As soon as you audible, watch how the outside CB's react. If they immediately run over the WR's, the defense is in man. If they slide to the outside and slowly come over the WR's, the defense is in zone.
Now, as I said in the setup, you can use this tip by basically coming out in a spread formation and aubiling into a compressed set.
Step 1. Once in your desired formation, motion one of your WR's
Watch the defender guarding the motioned WR.
If he slides with the WR, the defense is in zone.
If he runs with the WR, the defense is in man.
The defender is running with our WR. It is man coverage.
The defender is sliding with the WR. It is zone coverage.
I feel that knowing whether defense is in man or zone before you snap the ball is very important and will help you improve a great deal on offense. This gives you a much better idea of what to expect once you snap the ball. It also will let you know which of your reads you should expect to be open and in what order the progression of your reads should be.