Step 1: Blend in with the living. Wear a good wig and some nice clothes. Don't be that "I'm a reanimated corpse" type, we don't want to spook the neighbors.
Step 2: Get a good lawyer. You'll need one for all the times you'll be sued for "property damage" and "excessive decomposition."
Step 3: Learn some basic self-control. No more "braaaaains" or "I'll never be sated" business. You're a functioning member of society now, act like it.
And remember, it's not about being the most fearsome undead creature, it's about being a productive member of society. Unless, of course, you're a zombie, in which case, just go ahead and terrorize the local shopping mall. We won't judge you.