I followed the size guide and ordered a L. I have a 29-30" waist and small chest. Fits really well, and looks cute. Fabric feels nice. The pattern isn't matched on the seams though. I think a $70 tshirt ought to be pattern matched.
last time i bought one of these shirts i got them in a size too small, but when i sized up to the proper size it fit me super well! just double check the measurements before buying, but besides that i love it :) doesn’t hug your body too tight either!