I dunno what level of designer you're looking for, but you may be able to find one that offers some sort of money back garuntee or is cheap enough (for you) to just try out and see if one out of two or three work for you.
Additionally, it may be fun to learn to become more fashion-conscious, if it's described to you in the right way (ie very clearly and rules-based). I'd say there's probably two major things: grasping certain principles (ie clothing is to bring attention to your face) and to cosnciously observe a lot of people who you think are dressed well, which is just an intuition call. Alan Flusser's books are pretty good and you can read a couple of books on this topic to get an idea of it:
Amazon.com: Dressing the Man: Mastering the Art of Permanent Fashion: Alan Flusser: Books
Hmm, it'd be a great idea if someone wrote a Geek's Guide to Clothing Themselves and actually help them develop that aesthetic eye. It would probably be quite successful.