Measurements.
Manufacturers' sizes vary with the manufacturer and the price.
I bought a cheap ($50) Chinese dress last year that was marked 5XXL. It was too small.
I have an Eileen Fisher that is marked L and it fits perfectly. And retails in the $250 range.
Bust, waist, hip. Length.
Shoulder to shoulder.
Upper arm (for plus sizes).
Shoulder to waist if there is a defined waist.
A clear and simple Terms of Sale.
You could check mine-- but I do ship internationally. Don't ship outside the USA until you have Detailed Seller Ratings showing or outside USA and Canada until all restrictions on receiving your customer payments have been lifted.
Accept returns. You are going to give refunds so you may as well get the unwanted item back.
Otherwise, your feedback recieved and left is your best public relations.
