I wanted a highly padded nylon inside-the-pants holster for my Kel-Tec, which I carry hiking, fishing, camping, etc. I couldn't find any that had enough padding to not irritate me after having worn it for a couple of hours under extreme exertion, such as summer hiking.
I took a heavily padded, generic"multi-fit" holster, put my Kel-Tec in it (unloaded, of course), then using heavy nylon thread and a leather stitching needle, stitched around the gun through both sides of the holster. The stitching followed the outside line of the gun very tightly, so in effect, I made the holster custom fit the Kel-Tec.
I also customized all my Fobus holsters.
I turned my oven on "warm", and put the holster in it for about 5 minutes. I took them out and put the gun in the holsterwhile theywere still hot, and let them cool overnight. They now fit the guns tighter than they did from the factory.
I also replaced the belt straps on my shoulder rigs with a stretchy, rubbery strap to goaround my belt Now the rigs are held close to my sides, but if I have to bend over, the belt straps give just enough to allow freedom of movement.