If your finger is 3/4" wide, or less, at
your first knuckle you need Small Picks.
If your finger is approximtely 7/8" wide at
your first knuckle you need Medium Picks.
If your finger is 1" wide, or larger
at your first knuckle you need Large Picks.

Difference between flat, round and brass picks:

There is a little difference in tone with the round face, slightly fuller.  The round face is considerably stiffer which can be a little more accurate.

 For those who like their pick curled around the fingertip, the stiffness of the round face makes that a little more difficult, although not impossible to adjust. If you like a pick that's easy to adjust around the tip of your finger, use flat. If you like a stiffer pick, use round.

If you like the brightest sound you can get, use flat, nickel silver.  If you like slightly diminished brightness, use brass.

Sizing your Picks!

To determine your pick size, place your middle finger on a ruler and press down lightly. NOTE: pictures on the screen are not true size.