Only ask one question at a time. Act like everyone in Thailand has ADHD. If you ask more than one question, you're getting an answer only to the last thing you asked.
Step OVER the threshold to any house you go in. Thai tradition holds that a spirit lives in the threshold. And think about it: if you were a ghost living under a piece of weather stripping, would YOU want to be stepped on?
Don't expect anyone to make plans. In America, that friend who responds to every invitation with, "Maybe I'll stop by!" is typically at the bottom of your list of preferred social contacts. But Greeks value their freedom and commit to plans only sparingly. So don't be offended if you can't lock anyone down.
Beware of thrown salt. A Greek legend says that salt will chase unwanted guests from your home. This is your warning that you may be given a hint.
Don't sweep over anyone's feet. Even if you're a good enough guest to help your host clean their floors, don't sweep anything over someone's feet. Spanish superstition holds that sweeping over one's feet means they will never marry. (Sweeping someone off their feet, different story entirely.)