Watch the Just Talking online guitar lesson by Angus Clark from Essentials: Rock Rhythm Unplugged

There are a lot of choices in putting together a finger style pattern. If you play solely the bass note on the downbeat, you lose some of the impact. If you play your highest note as a part of the voicing on the downbeat, you're missing an opportunity to create a variety across the bar. By creating a solid pattern in your right hand, you can take most of the guess work out of this.

The most important thing is to create a consistent pattern that allows you to create the "slap" against the guitar on 2 & 4 in order to get the desired effect. There are a couple of moments where we break from the pattern. These are purposeful and create a different dynamic. When the chord is arpeggiated and ringing, it makes a more open sound that contrasts with the pick/slap pattern.

Lessons in this breakdown:

Thumb + index/middle + ring pattern.
How to get the best "slap" sound off the guitar.