Watch the Muted Strumming online guitar lesson by Brad Carlton from Guitar Lab: Solid Strumming
This lesson covers something that many students find interesting as they are always concerned about getting a clear ringing sound of the guitar. What we're after here is a percussive effect to contrast the ringing aspect of the guitar. This technique can be used in a number of different ways. When played aggressively, he fills out the sound and actually drives the music. When played lightly, which are termed ghost strokes, they enable you to stay in the pocket and they also aid in keeping your pick stroke direction where it should be.
Muting of the strings with the fretting hand is the challenging part of this technique. Because of the occurrence of natural harmonics at various node points along the string, you may get bell tones even when you're muting the strings. This is where you have to use different parts of different fingers to mute the strings in locations that don't have these node points. You also have to acquire a light touch so they are not pressing down any strings enough that they can ring. If you're running an extremely low action, this can be a disadvantage for effective string damping.