Sectioning tends to be a huge deal in the hairstyling industry and this video shows you why.  Teasing and spraying play enormous factors in delivering volume to this clients head of hair.  Sectioning off chunks, teasing then spraying then flattening out again appears to be the way to go to successfully achieve the end result which is more body and bounce.  Finger twisting will add much needed curls through out the hair to build the illusion of even more fullness.