One of the most common techniques for blending hair is using either scissor over comb or clipper over comb technique. It allows you to go to the areas that need blended and remove the weight. Remember it is all about tool position!!!
For a man who is thinning/balding on the top to blend the sides in so it doesn't look so "Monk" like cut the hair closest to the horse shoe are shorter than the rest. Pick the section of hair straight up as you would with a long layered cut.
To Blend a fade use thinning shears to take some of the bulk out of the weight line. When the weight is removed the hair will blend and the client will be happy :)
