I rarely put anything on my legs, be it tights, or warmers, just don't like the feeling. I live in NorCal, so perhaps that's why, it just rarely gets *that* cold. And for my body, I don't really recognize "cool". It may start off cool, in fact I may be uncomfortable for 10 minutes or so, but once I warm up, I just don't get cold again. If it's cold enough, I'll put on knee warmers (IMO, thinner is better, the thicker ones tend to bunch behind the knee, and don't stay in place very well). If I need something on top, I have a very thin, stuffable cycling jacket. The key is getting one that is FITTED. Nothing worse than feeling like you are a wind sail, and the associated LOUD flapping. For me personally, it doesn't take much to keep me warm up top, so a very thin jacket works well, inevitably I end up taking it off. Another plus to a very lightweight thin jacket is I can just wad it up and stuff it under my jersey if I'm moving and don't want to stop to stow it properly in a pocket.

Oh, I do use arm warmers. My arms can get quite cold, even in "cool" weather, but IMO arm warmers are all the same. One brand is as good as another.