I do sound in a few situations -
One band I work with treats me like a member. I sit in, I do sound, I announce them sometimes, I setup tip jar, do a little extra with lights here and there - get them drinks here and there (mostly when its hot - and outside shows can be brutal - I ALWAYS get pitchers of ice water and glasses on these shows for them)
They ALWAYS mention me - and send thanks on the Mic
They always support me if something is off, or goes wrong. We try to fix it.
They always pay me well, give me a share of tips, and comp my food/drinks, even when its not covered by the venue.
They also help me load out at the end of the night and sometimes if they are there at setup.
most others don't tip me, but every now and then - I get comps from the national acts, or something along that line.
the classy guys always do SOMETHING........and treat me well. It goes a long way with me. A CD, a shirt, both, tickets, something........and just being treated well, and included in the conversation is huge.