The technique known as percussive strumming is one of the most common techniques used by rhythm guitarists. Hold an F bar chord shape, but apply no pressure to the strings. Your left hand fingers should be just touching the strings (to deaden them). When you strum the strings the resulting sound is known as a percussive strum.
A percussive strum is indicated by a cross placed above the wedge mark, as illustrated in the following example, with percussive strums on the second and fourth beats.
Rhythm Pattern
Apply this rhythm to the next progression in F.
Rhythm Pattern