I haaaaaate to wear unpadded tights over shorts! I've tried a few different pair, but I always end up fussing with them at some point during the ride because they've slipped or rotated or something else obnoxious.

I have one pair of pretty thick bib knickers that I use for super cold days as well as a not-as-thick pair of non-bib tights and bib knickers. Strangely enough, I've never had an issue w/slipping leg warmers unless I don't have them pulled up high enough.