It is actually very easy to make the switch from conventional shampoo and conditioner to none at all. Previously, I was purchasing very expensive "organic" shampoo. It was still filled with about a hundred different ingredients and it was certainly breaking the bank. I knew there had to be a better way to be green while still maintaining a clean scalp.
I started with a simple Google search and the first website I found had exactly the advice for which I was looking. The answer was just so simple: baking soda. I began using about a teaspoon on my head every three days for a year and haven't looked back. It's incredible! The benefits became very clear early on. I no longer needed to purchase shampoo. This cleaning method helped me to balance the natural oils my scalp creates, causing it to not look greasy or oily even after 2 or 3 days of not washing.
I should be clear: everybody's head is different. Just like there are different shampoos for different hair types, there are also different combinations of things you can use to create your perfect recipe. Some people will need more baking soda, some less. Some may want to use a little vinegar after as a sort of conditioner, leaving your hair silky and workable.