In some cases, the first customer is the hardest one to get, and there is no secret. People need to trust in your business to buy from you. The best way to start developing trust is by talking to your family, relatives and friends. Probably one of them would end up being your first customer. But your real concern should be how to create such a great experience to that first customer to make him talk to others about your product/service... make sure you do, and you will start receiving customers fluently.