I like to be payed before I start.
I'm willing to redo a piece how ever many times until it is satisfactory, even with detailed painting. I feel like it's important for a client to get exactly what they wanted.
If you don't want the piece after I've already made it I'd want to discuss how much it should be refunded. I understand not having money but even a 5 dollar reimbursement for work would be nice.