Get there early to park in the neighborhoods so you avoid the $20 or whatever it is for parking.
Common sense, but you want to enjoy the game, not stand in line to whiz, so don't drink much.
DO NOT LEAVE THE GAME EARLY! Fortunately most packer fans don't, but we need to take pride in not leaving until the final whistle, whether they're up or down by 50. I've always done my part and stayed to the bitter end even during the vick/falcons playoff loss (ugh, still painful memories)