To become a good rhythm player it is essential to have control over where in the bar you place notes or chords and where you leave spaces.
One way to improve this ability is to take each subdivision of the beat i.e., eighth notes, triplets or sixteenth notes, and practice moving each one to all possible positions within a single beat and then within a bar. To keep the feel of the basic subdivision, use percussive strumming in place of rests. The next example contains exercises using eighth notes. Play the exercises as written at first, then try swinging all the eighth notes. Remember to use your metronome, count out loud and tap your foot evenly on the beat.
A simple power chord rhythm can be made to sound "heavier" by applying an accent to some of the strums within the rhythm. An accent is achieved by playing the strum a little louder or stronger. An accent is often shown as a small wedge (L) above or below the note, as shown below.
The following example applies the accent to a simple chord progression that uses the open power chords A5 and E5.
A good way to gain control of accents is to take a systematic approach similar to the earlier percussive strumming exercises and practice accents on all possible eighth note positions within a bar individually, and then in combinations, as shown below.
It is also important to work on using accents with single notes. A good way to do this is to use the four finger exercise from the start of the book and play it in eighth notes, first accenting all the notes on the beat, and then all the notes off the beat, as shown here.