Knife sheaths are made with a welt around the entire blade then hand stitched to the back and front piece of leather. No rivets are used because they are not needed with the hand stitching. I don't typically make the folded over leather sheaths that are common simply because they are designed to be quickly machine made.
I can also overlay your Kydex sheath, if you want something that looks a bit nicer than black plastic surrounding your knife.
Most often I will need your knife, or at the least, several pictures that include the knife next to a ruler and the thickness of the blade. It is much preferable to have the knife in hand when making a sheath. If you send a knife, wrap and package it carefully before shipping. Two knives have been lost in the mail that were sent to me. Tape is your friend on the outside of the box.
If you elect to have me make the sheath using photos of the knife next to a ruler, there is a $50 extra charge for this. I don't like charging extra for that, but it takes nearly twice as long to make the sheath this way.
Thumb-Break Style Knife Sheath
Knives that have holes in the handles can have sheaths made with a thumb-break style retention. This is where the back of the sheath comes up just past the first hole in the handle, and a copper rod is placed so that it fits into the hole. You push the top of the sheath away to release the knife.