What I've finally gone with is just my thumb/finger-tips on 6 and 12-string guitars, but I'm still using Dunlops plastic thumb/finger picks on Hawaiian guitar, Dobro, Autoharp, and banjo.
Here's a trick that I've found is handy...to get thick plastic thumb/fingerpicks to fit "just right", dip either the "blade" or "ring" of said pick in boiling water for about 6 seconds, shape it into the way you want it, then dip it into ice water for 6 sec.(Don't try to do the entire pick at one time, tho, just the ring or the blade!)
To further this idea, a freind once cast my "pickin' hand" in bronze. The 1st time she tried it, it came out wrong, so I talked her out of the flawed hand, cut off the thumb and 1st and 2nd fingers and I use them to "mold" my picks around.
Look cool in my gig bag, too! ;-)