Your goal is to eliminate as much, if not all, of the risk in the transaction for your client. When you take away the risk, you lower the barrier to action and eliminate the primary obstacle to buying.
Aggressively let your clients know that if they are dissatisfied, you will give them their money back, redo the job at no charge, or whatever else it takes to demonstrate your total, passionate commitment to their satisfaction.
Clients will take advantage of this risk-reversal strategy and very seldom ask for reimbursement. But the offer will serve you 100 percent of the time.