This is what I have been doing.
1st round - Raise once. If all the NPC's fold then YAY!. If they don't all fold, I'll call.
2nd round - Raise once. If they call I fold and wait for the next hand. Usually after this raise, all the NPC's are out, since some of them had already folded in the first round.
Once they've all folded either in 1st or 2nd round, then we do the normal call betting until the 6th card is shown. This is when we start raising, raising, raising lol. When I've given the amount of money requested, I'll then fold, and they get the winnings.
Good luck