i learned this in cosmetology school. hope this helps.
the best place to wash your hair is the shower, with head tilted back. this way the water is able to flow better through the hair and the hair is not piling on top. doing this helps to avoid tangles. rinse the hair and scalp properly. make sure every strand is wet. this should take a few minutes before you add shampoo. use lukewarm water.
use only the pads of your fingers to cleanse and massage the scalp. do not use your nails. using your nails can cause tears, cuts, scratches, and breakage. do not pile the hair on top of your head and only cleanse and massage the scalp. do not rub, srub, or massage your hair. this will create tangle, breakage etc... allow the water and suds from the shampoo to flow through the strands to cleanse the hair. (rinse process).
if you have a lot of buildup repeat or clarify the hair and scalp first before using your moisturizing shampoo.
after you have rinsed all of the shampoo out, towel dry your hair (plot the hair with the towel, avoid rubbing). proceed with conditioner. don't apply conditioner to your scalp. the conditioner is for your hair.