Match thin sweat pants with classy accessories for a look appropriate for a wide variety of settings, even in the casual business world. To be sure, this look isn't for everyone and requires a bit of gusto to make it work.
Avoid matching sweat pants with sweat shirts unless headed for the gym. For a flattering look, wear high-waisted pants with tapered legs. A number of designers now make a contemporary sweat pant that is more structured then older types. Finally, remember that fashion is very contextual. A nice pair of sweat pants might work great in an informal work setting or a club but not work so well in a more formal environment.