Watch the Contrary Motion Turnarounds online guitar lesson by Joe Dalton from Acoustic Blues Handbook
These turnarounds cover a lot of ground. That is to say, we have the bass and melody simultaneously. I think of these as chord forms. I memorize the forms and the progression. Work on them slowly. As you speed them up, be certain to hold each of the chords long enough so there is a smooth flow from one chord to the next. Otherwise, the entire phrase will sound choppy.