I totally find titles to be the hardest part...other than a snappy synopsis!!! Both of these things are utterly beyond my feeble skills. So I pretty much do what you do - I nick song titles or find a sequence of words in the fic that can be lifted and still make sense.

There was an author in Stargate who used to have the best titles. They were always one word - usually an obscure one that I'd have to go and look up. In an effort to emulate such cleverness I have on occasion decided what the theme of a story is and then used a thesaurus to find related words to use as a title. Meh! Sometimes it works, sometimes it doesn't.