The keys to billing per project are clearly defined specifications, signed contracts, and down payments. Give your hourly rate in addition for work that goes be

The keys to billing per project are clearly defined specifications, signed contracts, and down payments. Give your hourly rate in addition for work that goes beyond the spec. Both you and your client benefit from knowing exactly what they're getting and for exactly how much. Plus, a concrete spec and price will help them get the expenditure approved, when applicable.