Tips for a new Umpire

[McMac]

I started officiating tackle football last season as a LM, but have transitioned to U as our association is short of U's this season. So I am looking for tips/'things to look for' from those of you who have worked as a U.

I have noticed in the few scrimmages that I have had so far that it is a lot easier for me to pick up the run/pass blocks at the snap than when I was working as a LM.