I don't use a dress guard. My dresses are mostly knee-length and an A-line cut, so they really couldn't blow back and get caught in the spokes. My coats also are either waist-length or tailored closer to the body, so I don't see an issue there either.
The best trick I've picked up about wearing skirts and dresses is about how you stop them from flying up. This is super simple: you just clip a binder clip or two to the hem to weight it down. Works perfectly. You just have to remember to take the binder clips off when you get to work!
And now, because I never pass up an opportunity to share a picture of Sassy, my bike, here she is:
by Giant Doofus
, on Flickr[/IMG]