Here is what I do a couple times a week, either at sink or in shower:
Wet hair, dissolve 1/2 cup baking soda in warm water, pour on hair, rub in. This will exfoliate the scalp and hair follicles. Next I pour 1/2 cup vinegar over my hair and let it fizz. Scrub and massage in, I let it sit for some time, say 2-5 minutes. Then rinse.
My hair is soft at root and sometimes a little dry at ends, for not using commercial shampoo and only using this concoction it cleans my hair very good and my dandruff is under control. Here is picture of my scalp. Our son, we just noticed, has some dandruff on top of his scalp. I'll start posting on him to show the progress of using the baking soda and vinegar concoction to reduce dandruff.