oh zella leggings. my one true love. I buy a pair every year at the anniversary sale. They're just the right amount of weight to cover everything, but light enough to stay cool during a work out. I literally "live in" outside of work.
however, I don't think the sizing chart here is accurate - I'm typically a sz 4-6 and I think they recommend a small here, but I find a medium much more comfortable. personal preference maybe? Regardless, this is the best pair of leggings for the price, even when they're not on sale.
I found these to be true to size. I am a 0-2 in pants and the XS fits me perfectly. I really like the waistband on these- not too high and not too low. The material is nice- a little thicker than most athletic wear and not shiny! I'm glad I found these and I'm sure they will get lots of wear!