I use bar soap (actual soap, not the a bar of SLS. Currently I'm using an olive oil lavender soap from Kiss My Face, but sometimes when it gets grungy I'll use ivory soap) and follow that by dumping diluted vinegar on my head to rinse away the soap scum. I also use conditioner as I normally would. I have very fine hair, and absurdly sensitive skin. Using SLS shampoo caused tons of flaking and really limp hair because my scalp was so sad. My hair is a bit nicer looking than before, but mostly I can now wear black shirts. Also, it takes about a week to get greasy now.