I’ve had reasonable luck with eshakti, which does made-to-order clothes. You pick the dress, send in your measurements and whatever alterations (maybe you want it shorter or longer, or to have different sleeves), and there you go. I have no idea how returns work, but I didn’t have to return any of the things I ordered…because they fit.
I’m slender but busty and short-torsoed, so being able to buy a shirt dress that buttons up the front but doesn’t gap is some kind of miracle. However, my actual favorite part is that I can sort the clothes on the site by fabric and color, so if I only want to buy (for instance) green cotton clothes, I only have to look at green cotton clothes. That takes out a lot of the annoying and overwhelming parts of shopping.
The stuff I’ve bought hasn’t been very flashy (I like flashy), and has been pricier than what I’d get off the rack, but it’s held up well; it’s good-quality fabric, sewn sturdily. Tends to have functional pockets.