This is maybe the natural recipe I'm most pleased with. It works fantastically and has completely eliminated my need for conditioner, which is a plus because although I love the Aubrey Organics conditioner I was using, it's very expensive.
I started doing some research online about natural shampoos and kept running across the same ingredients: baking soda, apple cider vinegar, and tea tree oil. Baking soda is a cleanser, ACV is an anti-dandruff and conditioning rinse, tea tree oil is anti-fungal and a dandruff remedy.
It seemed like most people who were using natural methods were making a baking soda paste to clean their hair and then occasionally using an apple cider vinegar rinse.
So I tried that for a while. I made a paste with 1 TBSP baking soda, 5-10 drops tea tree oil (any more gave me a headache), and enough water to make it workable. I spread it over my scalp and left it for a while before rinsing. I'd then rinse with apple cider vinegar.
The only problem was, it stripped my hair incredibly dry. Even using conditioner didn't completely restore it.
Finally one day I tried mixing the apple cider vinegar and baking soda BEFORE putting it on my hair. It foamed fiercely, as such a mixture is prone to do. I used it, rinsed it out, and immediately noticed: no dryness. In fact, I didn't even need conditioner. It made my hair sparkly-clean and didn't dry it out whatsoever, unlike shampoos.
Now I'm hooked. I mix 1 TBSP baking soda with a splash of ACV (it turns out kind of runny, not a paste). When it stops foaming I mix in 5 drops tea tree oil, pour it over my hair, work it in, leave it while I shower, rinse it out (rinse thoroughly to make sure you don't leave any residue), and voila. I still haven't needed to use conditioner and my hair is shiny and soft. It seems a little bit too good to be true, especially since the main ingredients are so inexpensive.