All good advice. Doing business can be like a game. It doesn't matter how you play it as long as you can do well with it. Once you know your breakeven you can...

1). Do Free Estimates and boost the rate of the first task.
2). Have a Service Charge to cover travel, setup & cleanup, and keep the first task normal.
3). Have a Minimum Charge that covers travel, setup & cleanup, with normal task rates.
4). Whatever else will work for you.

The main idea is to recover your overhead and earn profit. The method you choose to do that may depend on your territory or your business style or your comfort level.

Dave