6.4 The G Chord - Advanced Strumming video
Tunefox Guitar Lesson #6
Alternating bass for the G chord is a little different than what you've done so far because you're using the 6th and 4th strings.
The alternating bass pattern you'll use for the G chord is 6th string then 4th string. You haven't skipped a string in these lessons, yet so this may be a little uncomfortable for you. Take it nice and slow and even look at your right hand to make sure you're being accurate. After you've practiced that and gotten the feel of it, move on to adding your bum-ditty.
The G Chord - Advanced Strumming Guitar video lesson
The first measure in the tab below shows the basic pattern. Practice this first and then loop the second measure to practice the bum-ditty pattern using the G chord.