2) Don't stand in the middle of the sidewalk to take a picture. I can't emphasize this enough. It's obnoxious, and even though we're being polite and stopping for you, we're secretly dreaming of snatching your camera and throwing it in the nearest puddle.
3) Squirrels (and other wildlife) are great. They're cute. But please don't stalk them while trying to hand them food. They're not coming home with you.
4) Don't be rude when asking for directions. You just may end up in a part of town that's not so great for clueless folks like yourself...or we might direct you to a street that doesn't exist and leave you wandering downtown, confused as hell. (Tip: If someone directs you to J Street...don't listen to them.)
5) Accept the fact that you're a visitor. It's OK. Trying to be hip and blending in with the locals just makes you even more annoying because (I'll clue you in on a secret) WE CAN TELL you're from out of town. And that's OK, just so long as you're not being an obnoxious twatbag of a tourist.