To add to the film thing: if travelling with film, keep it in carry-on bags and ask for hand checks. Film gets exposed by the radiation from machines at checkpoints; the higher the ASA, the more it'll get ruined. 400+ will for sure be destroyed by a scan or two.
I ruined 4 rolls of the best street photography I've ever done from a trip to chicago because I didn't know about it.
Not all of it though. I remember Blue from Overly Sarcastic Productions going on a tangent about how he went over to florence (or venice) and looking for a place that didn't exist. Ubi had made it up completely.