Thin pick for strumming.

Thick pick for something like church picking where you play a lead bass note and then sort of flop the pick across the three teble strings and back. A difficult style to do well. A guy called Dil Davies used to play this style beautifully on the English scene. Anybody heard of his whereabouts? Rambling Jack Eliot - didn't he do this sort of thing? I know he was Dil's hero.

Brian May used to use an old sixpence to play his leads. That is to say very thick.