I am sure you have heard this but these are things I do. Know your mechainc's keys. Start inside the goal posts and try and work inside from hash to hash as much as you can during the play. Read the play. I never step back at the snap. I read pass then I step back a few steps. Stay deeper than the offensive players coming up field. Never whistle out of your area and never signal out of your area. See the whole play because our stuff is big most of the time. HAVE FUN!