Watch the Open G Exercise 3 online guitar lesson by Richard Gilewitz from Fingerscapes

This very simple riff in open G tuning allows the player an opportunity to practice pull off's in time as well as a chance to avoid the typical alternating bass style by inserting a reverse a, m, i arpeggio in measures 2, 4, and 6.
It is a good idea to take this practice exercise as an opportunity to work with your metronome and remember to play the last chord with a right hand strum with 'p' (your thumb) in a relaxed and restrained manner allowing the music to 'breathe out' as opposed to an abrupt and rushed ending.