I know two methods, but they still involve occasional shampooing (at least once every 2 days).
The most fashionable and simple option is dry shampoo. I didn't use it myself, but I read good reviews even on budget products
My personal method. I have curly and oily hair. I do a gelatin hair mask in the evening. I dry my hair naturally, then I style it with a curling iron. After sleep, the styling still holds up pretty well. The next day I comb my hair, the styling becomes more natural. So I can not wash my hair for up to 4 (sometimes up to 5) days. The method is quite time consuming, but worth it.
The most important thing is to learn to wash your hair less often, to touch it less and to shift it, you also need to comb it less often
Dye your hair. They will be slightly drier and not greasy every day. At least 3 days before the next wash, you should be able to look pretty decent. Various sprays, mousses and styling will also help, pick up empirically.
My head every day, or at least every other day, to be clean. But people often say that washing so often is harmful. Is this so?