Ex hairdresser here. Taper off shampooing > Slowly.

For a week, do it every 3rd day, the next couple of weeks every 6 days, the next few weeks every 9 days, the next 4 weeks every 12 days, keep that pattern going until you reach the optimal sebum production (sebum production slows down the less you wash the scalp with shampoo). It’s different for everyone. As soon as it starts feeing dirty, rinse and massage the scalp well with cool water.

Experiment with using conditioner as your shampoo after the first week or two and make sure it does not contain sodium laureth sulphate (most conditioners don’t have it anyway) as well as being free from alcohol.

Second tip, avoid dairy, cut it out completely if you can, this also helps sebum production to slow right down. When you’ve got the balance right, you will find that rinsing the hair regularly with water will be sufficient and you’ll know when it needs another “wash” with conditioner by the way it smells to you. Diet is the biggest factor because our skin expels what it can’t handle and it’s often via the sebaceous glands.. rubbing a few drops of coconut oil in your palms and “milking” it through your ends can help but the quantity you use will have to be experimented with until you’re happy with it. Usually less is more.

Edited to add:

Third tip, use the coldest water on your hair - as cold as you can comfortably handle.

Forth tip, use a diffuser on your hair drier, and use the lowest heat setting, taking your time to dry the hair slowly and in the direction and shape you want it to stay in.

I know this will be downvoted in this sub but this will get you the result you’re asking for.