Here in the US, HerRoom.com is a very good online source for lingerie (there are others, but I have had excellent experiences here). They are very male friendly, and if you go online with a question, you will be helped in finding your size in all things lingerie, including shapeware. As for panties, i go to the size chart for the brand of pantie l am interested in, and go by the hip size that is closest to my hips. The waist typically will stretch enough that they are not binding nor too too tight. If your waist measurement is larger thatn your hip measurement you will probably want to use the charts waist size instead of the hip size. If you want to buy from a local store, you can still get an idea of the proper size by looking at the size charts. If you are new to panties, the advice to buy inexpensive panties is very good until you find “your” size, and style, that will usually be the same across all brands. Good luck in your search, and once you find the size and style(s) you like, you very likely will never go back to mens underwear because the fit is so much better, and more comfortable than the male stuff. YMMV.