Some QB's have little trigger mannerisms they do before the snap which can be helpful.
TE off and to what receiver?
Is he looking for the heel of the QB?
Motion is a great timer. Motion usually extends to certain points by who is in motion.
- RB/TE = Usually in Box/D gap area
- WR = Usually extended outside the core or can tell by when they slow down. Flip (#1 off the LOS, #2 on in a twins formation) us sometimes a tip for Z-in (Crack) motion.
Get a feel for opponent's cadence. Usually when they use a Color # / Color # in their cadence, they say it twice (once to each side) and then make the "Hut-Hut" calls. We can time off of this.
Get a feel for quick counts / first sounds by the offense's body language and any changes in normal routine.