Watch the Open String Chords online guitar lesson by TrueFire from Play Acoustic Guitar 4: Rhythm Principles
There's something magical about open string voicings and you simply can't have too many of them in your chord vocabulary. They're challenging to construct because the open strings have to be harmonized by key and chord type. Brad Carlton presents 6 open string studies in this third and final section.
TIP! Everything you work on should be started slowly, paying attention to the fine details of finger placement, minimum motion, efficient picking hand movement, and proper intonation. Then GRADUALLY increase your speed. Think baby steps. Don't try to jump from zero to 60 - take it slow. As you gradually speed up you will see other technique issues that need to be addressed. These are more easily discovered and dealt with at slow tempos. It is way harder to fix a problem that you have burned into your muscle memory than it is to just start slow and fix things along the way. So always start practicing a new thing slowly, and then build up your speed.