Manual Stretching and Extender

I have been PEing for about 4 months now, and do a basic routine of manual stretching, and girth exercised, as well as using a combination of extenders. The X4 Extender and the Vac Extender.

My question is what are the best manual Stretching Exercises to do in combination with extender use? Do extenders increase ligaments and tunica at the same rate?