Hogar, I have found that using a Dressage Whip on a bottom and thighs can leave really nice welts. You can buy one for a few dollars at a Farm and Fleet type store. The Dressage has a hard shaft that can cause damage if used too hard. It also has a soft tip that can be used to leave nice welts without too much pain to your sub. It takes practice so start out slow and easy... Good Whippings