I'm at the point in numbers that I often have to look carefully to make sure I'm not trying to duplicate a previously used one, though, and that sometimes means I don't really title a work what I want to call it.

Since I've picked up the habit of writing serials (which need each piece to have a title, as well as the overall serial title), I'm much in the same boat. And I have accidentally duplicated one, but I didn't notice until long after I'd posted it. Oh, well. I'll usually try to at least get close to a word I'd like to use and then maybe make a synonym run on it to find the perfect one :P

I have no theory or strategy...I look at the work, and slap a title that seems fitting on it.

This is pretty much what I do as well, but sometimes I'll have an idea in mind first that might help direct the way I want to write a piece (most recently, "A Most Favorable Arrangement," which meant I had to write it in a higher style of prose than I'd originally intended...)

What I'm stumping on more often now is trying to write a summary. I don't really do either (titling or summary) until after I've finished writing a piece, but more often than not I can't find a good way to summarize what I've written without it sounding horribly trite or cliche. Bah!