Permission trumps forgiveness.
Always make sure your permits are in order before lighting anything on fire. If you’re not sure if you need a permit, find out first. A pleasant phone call and a $35 permit fee are much preferable to a steep fine or worse.
I’ve never once regretted talking with the police before filming an outdoor scene. Each time there was trouble (and I know of several incidents involved with our last production!), the police already knew about everything and we were perfectly legal and nice. Zero hassles (although for one incident, we had to stop filming for an hour or so until the cops found all the lost terrified teenagers, but we needed a break anyway).
(thank you, Brian Oberquell)