Watch the Week 7: Diagonal Rolling Shifts online guitar lesson by Derryl Gabel from Fretboard Intensive Training
Here we have examples of diagonal shifting for each position. When descending, you will play an eight note motif and then shift up everytime. This will allow you to ascend the neck but descend the scale. When ascending, you'll play an eight note motif and then shift down every time. This will allow you to descend the neck but ascend the scale. Keep in mind you can use different motifs with this concept. Try doing this with a 7, 6, 5, and 4 note motifs. By simply removing one note out of the eight note motif given in the example you now have a 7 note motif.