In reply to John Kelly: I try for and dream of granite, but due to time constraints spend a lot of time on grit...
Nuts of Choice:
1) Alloy Offsets, and peanuts for smaller sizes - these always seem to be placed!
2a) Wallnuts for granite or grit (generally rougher rocks where the complex shape beds in better).
2b) Rocks for limestone or other smoother rock.
(I've got some of all three due to either 'need for lots for TRs as someone in charge of a club with novices' or 'magpie-like acquisition of the shiny anodised gear' - I had a beaten-up set of classic rocks, which I supplemented with wallnuts, then realised how useful the anodising was so replaced the rocks, then fell in love with the offsets after borrowing them a few times...)