I have a 2 strike policy for that.

By this I mean if you give me an NSF check 2x no more checks for you. Cash or money order only.

I also have the "offender" pay a 30.00 fee, as well as any charges incurred to me by the bank, and if it is after the first they must pay my daily late fee too, so bounced checks at my dayhome aren't a wise choice