As someone who spent most of my professional life avoiding flash as much as possible I applaud your question.
I haven't avoided it out of fear or lack of knowledge either. I just don't (didn't) care for the look. You can shoot in a lot of situations without flash. In fact I see a lot of shooters, including pros, using flash when (IMHO) they don't need to or shouldn't be. That being said, my style is evolving into using more flash. But I'm talking about more complex flash setup than just on camera or basic fill. I still believe that flash is worthless (in most cases) for fill in anything but snapshots. If I'm shooting in natural light then I'm filling with natural light (reflectors).