Never overcharge your client. Value your time at the market price - 24 hours a day. Now look at what is eating up your profitable time. Cut out the unnecessary items, like the reruns of Gilligan and Oprah, sleep, fun stuff, until you make enough money. If you're having a negative cash flow - get a temporary job until things start coming through.
Marketing is the key.
If people don't know about your business, you will not get business. There are too many ways to list. Buy 'Guerilla Marketing', subscribe to small business magazines, keep a finger on the pulse of the consumer and fulfill a niche. How I did it, how I'm doing, how not to do it, who to talk to, how to phrase your application, and so on. It's a pain in the ass, but so is swabbing the ready room.