I've never charged, and my better half is like

when I tell her we have another service today. So going into a new church I would like to have this discussed up front. Prior to the last Pastor, now I see why he didn't want anything in writing, because you couldn't hold him to it.
You can comment on Weddings, 3pm services at your church, 3pm services at someone elses church, funerals, basically anything extra than the norm.
Ex. One Sunday I played at the normal service, went to a musical 3pm, then went to another church 6pm where I had to preach, and play for baptism service for our church (we didn't have a pool). I drove over 200 miles that Sunday. I was beat down. Oh, additional pay = 0.00 you guessed it.