Whoever created the myth that hair should be washed every day, was seriously misinformed. The fact is, the more one washes their hair, the more they are stripping their hair of much needed natural moisture. Over-washing will dry hair out, leaving ends fragile, brittle, and ultimately leading to breakage- so the less you wash the healthier your hair will be. Also, over-washing can also accelerate the fading highlights and colors, for those who dye their hair, as colored hair requires as much moisture and nourishment as it can get, to sustain its bright sheen and overall health.
The frequency of wash is determined by hair's texture - the finer and straighter strands are, the more quickly natural oils will coat and penetrate them. Finer, straight textures should aim for washing about every other day, roughly 2-3 times a week. Thick, wavey, curly, and coily textures should wash hair a maximum of 2 times a week, or even less if it can be helped. Curly hair has a natural propensity to dry out more quickly than straight textures, as the strand structure is less conducive to allowing the natural scalp oils hair craves, to coat the entire strands efficiently. The curlier the texture, the less frequently hair should be washed. However, no matter what your texture is, it is important to significantly space out the time between washes, as doing so will amplify hair's strength, by maintaining it's natural moisture.
Now, if you are already in the habit of compulsive washing, I can understand why the notion of this could seem strange. For how can you ensure a sweet, clean smell, soft feel, simplicity of styling, and lustrous look, with a dirty canvas? The trick to keeping your dirty secret, all comes down to two things: how you style and the products you use between washes. I suggest using a small amount of styler combined with natural ingredients and conditioning properties between washes if your desire is to maintain a freshly cleaned smell while avoiding icky, itchy product residue and adding sheen and shine. Miss Jessie's Multicultural Curl, Miss Jessie's Transitioner's Magic, and Miss Jessie's Quick Curls, leaves hair soft, smooth, frizz-free, and smelling great. Now I know these products are targeted for wavy, curly, and coily textured styling, but the natural ingredients of Safflower, Olive Fruit Oil Aloe, Coconut Oil, Ginger Root, and Apricot Extract, actually work wonders nourishing and moisturizing all textures of hair. Also, dirty natural hair actually makes styling much easier, as your natural scalp oils make strands easier to manipulate, than freshly washed hair. See for yourself!
Check out all the styles made easy on a dirty hair day: