Long time reader, first time writer. I have been working on leather for awhile now but I'm having trouble with my belts and my guitar straps. They seem to come out stiffer than I would like. I'm oiling them with neatsfoot and using fiebings oil based dyes. I want them to be more "supple" and flexible. (Especially my guitar straps. Frankly I can deal with stiff belts.) any tips would be greatly appreciated! Thanks!