I bill quarter-hourly at $300/hr for actual time writing or evaluating code. Phone conversations are free, and I take time to evaluate and explain what I'm doing before clocking in. The downside to this is that I make myself available 24/7 should any issues arise. I also don't necessarily charge for hunting down network issues or bugs (because I also host some software for clients). It works out to a good income for 80 hours a month or so.
I'm terrible at sales. My clients have only come to me by rererral from other clients. More than half the time, I'll tell prospective clients that there are already SaaS solutions that would be better for them than building something bespoke, and help them find solutions, because I don't want to do work that's already been done.