I use whatever I can get my hands on but prefer the medium guage standard size rounded triangular type. I have gone as far as cutting ones out of a milk carton. This, of course, being a last straw after searching under seat cushions and furniture. I like using a quarter sometimes...you can really do some nasty pinch harmonics with one...in fact it's kind of hard not to. We sold our house last year and as we were packing and moving furniture I found about 15 picks I had lost over the years....now I'm down to about 2 that are worn. I guess it's time to move again.