Watch the Fretting Hand Prep online guitar lesson by Brad Carlton from Guitar Lab: Caging ii V I
This lesson uses what I termed the "seed" principle. The seed is the initial exercise (examples 47 through 54). In each of these exercises the lower voice was the F note in the sixth fret of the second string. By moving this lower voice down through the scale form, you will develop more exercises which are like a vine growing from that initial seed. This is a very important principle in the practice of music as it not only broadens your technical skill but it helps you conceptualize musical options both mentally and aurally.