I got a M since this dress has no give, but I think I should’ve gotten a small. For reference I have DD cup (wore this braless) and a butt. Still the M is slightly big and makes this look like more of a work appropriate dress than a cute little summer dress. So, I don’t think you should size up.
Great length and quality. The pattern is really nice and overall was a flattering fit. Fabric is similar to Reformation, maybe a little thinner with a liner underneath.
I really like all my items. They are all good quality and the fit is great. Will order more!