This is really geared toward electricians in residential service with a few years experience. If you don't have that experience, start keeping track of the time it takes you to do jobs. For projects with plans, I try to get people to fax prints, or send plans. This minimizes the 2 hours travel & talk (this is my year to reduce unbilled hours).

1. Know your cost of doing business (covered at length in other posts).
2. Have a business plan and budget.
3. Use 1 and 2 to figure your hourly rate, which you will be using in the flat rate sales book. You will probably discover that you haven't charged enough in the past, which is why you don't...advertise, have a decent salary, a decent truck, decent tools, a retirement plan that will actually allow you to retire before you'll need back surgery, knee replacements, wrist surgery...whatever.
If you call around to charge what the other guys are charging, you'll be in the same boat as they are (many on their way out-of-business).

Dave