Watch the Open D Tuning online guitar lesson by Vicki Genfan from Essentials: Open Tunings

The intro and outro in this etude use a very common I - IV/I chord progression (D - G/D) which you might also use in a blues piece. Try this same fingering in the 5th and 7th frets - using a barre to get the major chord first and then adding the IV/I chord (2nd & 3rd fingers).