Find one client at a low rate and please the hell out of them. Then find another client, but increase your rates. Do the same; do anything it takes to get the job done ahead of schedule and to make the client as impressed as possible.

Eventually you'll find the ceiling in terms of how much you can charge per hour, but you'll have an entire mountain of reputation built by being fast, dedicated, and reliable.

I'm a student and due to a family lawsuit (dad's business partners ran off with the company's bonding money, fitting him with the bill) I can't get student loans so I freelance to pay my bills and to fund my own projects. My main philosophy when I'm working with a client (and I tell them this) is "the sooner I get in and out with this project, the sooner you do too" and I then sit down with them if they are available and work on it until it is done. It's not as feasible for programming as it is for designing, but the same focus on speed is killer as a freelancer.

I'm still finding work at $100/hr as a 22 year old freelancer, so soon I can finally begin leveraging my personal brand equity and my time to creating more passive sources of income, (i.e.: services and products).

Hope this helped a bit.