Know the Basic Material
Listening to the other players
-Try playing different chord voicings, or single lines in a different register.
Don't be a jerk.
Get there before the gig & help load in & set up.
Don't play too loud.
Lay back most of the time. Blend with the group. Groove with the rhythm section.
Learn to play "rhythm".
Know the material, including the songs you don't like.
And know them from beginning to end (at least the basic chords), not just the "good parts".
Help load out after the gig.
Don't be a jerk!