An interesting effect to use is thumb percussion. To apply this technique the right hand thumb hits the 6th string against the fretboard causing a quick rattle sound. The strike normally occurs on the 2nd and 4th beats of the bar, simulating the sound of a snare drum.
Listen carefully to the accompanying CD to hear this effect in example 27. Thumb percussion is indicated by a cross in a circle.
Thumb percussion is applied to the following progression.