Re: ettiquette question
I usually pick someone friendly-looking as soon as I arrive and make him or her my "local guide." Saves lots of embarrasment. But I still haven't encountered a dojo that actually lined up by rank (or if I have, I was totally oblivious).
The one that always catches me is bowing to the shomen: one bow? two? how many claps? But no one reasonably expects a guest to get this exactly right.