Pre/Post snap D.

Okay, I have been labbing offense and offense and offense. But I haven't even scratched the surface of the defense! So I know on O I read the D looking for man or zone. Recognize and adjust accordingly, after the snap I watch the LBS for blitz/hot read and throw to my open route combos.

Now, my question is WHAT should I be doing on Defense pre/post-snap? Perhaps a mental checklist of some sorts. NYJ is my defensive playbook, and I run with the Cowgirls. I am not asking for NANO's, I know those i'm looking for info that I can brainstorm off of. Thanks in advance.....

I watch for formations. Then what plays they like to run out of the formation. Its prolly 3 or 4 plays at the most, some ppl have more, some ppl have less. Then u gotta think bout the down. I mean thats what i do. I dont really kno of ne pre snap reads on D.