Heres my tip, bring your rig, set your sh*t up, tune and play you pansy.
Some of that is common sense and some is rubbish, of course use quality gear, of course tune up and sound check. But I mean, who brings a torch to set up with? I've yet to see a bass rig that I couldn't set up with my eyes closed, even the big complicated rack setups are stored patched together.
Oh and be nice and explain yourself clearly but don't be afraid to call the sound guy a w***er if he's burying you in the mix against your wishes.