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.
Use http://Meetup.com + attend Meetup events in your niche.
Network with organizers.
Be a guest speaker.
I've use this method anytime I'd like to test any part of a new or existing business...
Or bootstrap a new client list with people with tendencies toward big ticket prices.
Way more lucrative + easy for bootstrapping, then any paid mechanism I've used... since starting my first business in 1974.
Meet with people at networking events or asking for introductions through friends and family.
You want to find prospective clients and then meet with them not to sell, but to ask them about their needs within the scope of what you are selling. Use them as learning platforms, ask if your solution would work for them or what more you should do, and how much they would pay.
Get this right and they will be your first clients.
5 WAYS TO GET 5 CLIENTS (NOW)
1- Ask Family and Friends. If you're not willing to ask them, you'll have hard times with clients
2- Send an Email to a business owner underlying the fact that there are elements on his company's Website that doesn't work or could be improved. If he accepts, get him on a Skype call
3- The Drug Dealer Method. For instance, offer a trial for a week or two, or give something away for free first to get them hooked
4- Public Speaking. Growth Hackers Vin Clancy has built a 6 figures agency based on this strategy.
5- Use Linkedin. Connect with a lot of relevant people and then begin a conversation, see what the people's problem are