Watch the Turnarounds 9 online guitar lesson by Brad Carlton from Bluesology 1
Inversion of intervals allows you to get two different sounds from the same two notes. Also, the doubling of notes changes the sound and density. This can be very instrumental when crafting new turnarounds or tweaking existing ones.
This lesson covers these concepts along with the b3 to 3 move, large 4 voice turnarounds, and contrary motion - few more essential ingredients for your turnaround crafting bag.