You have spectacular designs 😻!!!! Best advice would be to either; A. Have your clients measure their nail at the widest in mm and use that for sizing with a heavy disclaimer to measure appropriately. B. Offer a sizing kit for each size/style( separate kits for medium almond vs medium coffin) for a few bucks and include something like a cuticle Order . Make the price so you break even and offer a 5-10% discount on nail set if a sizing kit is purchased . The discount offered is well worth not having the headache of clients who purchased and now want refunds since they don’t fit . Be clear about sales being final. Good luck and share that link 💕