I have BodyGlide, or a knock-off brand of it, that I got at a sports store that looks like a stick of deodorant. I keep it in my purse in the summer!
I'm also a big fan of wearing little shorts under my skirts/dresses. When I don't need anything slimming, my favorites are basic bike shorts from a sports store--City Sports has a brand called Avani or something like that which I find super comfy. Also, they come in multiple lengths...so you can make sure to get a long enough length to cover the irritated parts.
"I don't know! I don't know why I did it, I don't know why I enjoyed it, and I don't know why I'll do it again!" -BART SIMPSON