I've been a freelancer for over 10 years. Charging hourly rates has never worked for me. I charge by the project on agreed upon specifications, and I usually include a certain number of hours of site revisions into the initial project proposal. Any additions past the initial project will be additional cost the client must pay, though I do sometimes charge by the hour for additional minor site revisions.

For example, I built a site for a small business. They wanted a fairly basic Joomla driven website with seven menu items, some specific functionality with file storage and sharing, and they wanted a few logos and graphics designed. I also included in 20 hours of revisions. I charged them $2200, and when I had done 20 hours of revisions, I charged them $60/hr for the additional revisions.