I think you maybe have to find what works for you, though I'll throw another ten cents in.
Anth has given a short sharp starter answer: blacklist the whack-jobs and hotlist the potentials. Then once you have her in a hotlist you can easily keep all sorts of stuff about her on file as a 'notes' tab comes up with her profile. Fill it with as much as you can be bothered, eg her current name (for when she changes it), current charges (ditto), phone number (for when she can't afford to display it) and other stuff that may suit your mood requirements on a particular day ("outstanding knockers but smelly fanny").
The notes feature is an advantage hotlists have over blacklists, so if you live in an area where the volume of whack-jobs is small enough to ignore then a hotlist called blacklist is useful for showing why you want to avoid her as well as when she reincarnates herself with a new fake photo, name etc.
Another one I keep is UKP WGs (both good ones and nutjobs -- the latter to avoid and the decent ones as it is pleasant to be able to look at their profile when they are having a wee waffle about themselves (I don't punt UKP WGs: they are either like 'sisters' whose company on here is enjoyable or they are . . .).
You can also play that little game that better prossies play by noting some piece of shite and then introduce it casually as if you've remembered.
(I think the old 'guide to AW' that I wrote with another member is still kicking around somewhere, probably on the UKP wiki, and if not it's been nicked by numerous sites anyway.)
