Mostly use Dunlop Ultex .73mm for guitar and the same in 1.00mm for mandolin. Once in a while some other pick does the trick, usually also Dunlops, though a Wegan gets alot of use on mandolin. Have made them from tagua nut and various plastics just because I like to tinker, but always return to Ultex. I dislike providing store bought picks for students so sometimes they get my experiments.
I "dress" the points and bevels on my picks with very fine sandpaper to get as smooth an articulation as possible.