The most common complaint in this shop is a scalp that itches by the afternoon, and the most common advice given elsewhere makes it worse.
A scalp under a scarf spends most of the day warm and covered, and in this climate that means damp. Everything that lives on a scalp is happier in those conditions, which is why the complaints are so consistent: itching by mid afternoon, flaking at the hairline, a smell by evening, and roots that feel oily while the ends feel like straw.
The advice people are usually given is to wash less, because washing strips the scalp. That is true for a scalp which is dry and cold. It is close to the opposite of what helps here.
What we suggest, and what has worked for a great many people in this room, is washing more often with something mild enough to allow it. Every other day is fine. Daily is fine for a lot of people. The mildness of the shampoo matters far more than the frequency.
The second thing is drying. A scalp that is covered while still damp is the single biggest cause of the afternoon smell, and the fix costs nothing: five more minutes with a dryer on a cool setting, or ten more minutes before you cover it. If you take one thing from this, take that.
Third, keep oil off the scalp. Oil belongs on the ends. A heavy oil massaged into a scalp that is then covered for nine hours is how several of the worst flaking cases we have seen began, and they had all been told it was nourishing.
Fourth, look at the tie. Most scarf wearers have a ring of breakage at the nape or just above the ear where the fabric sits. That is friction, not weakness, and it is fixed by loosening the tie, changing where the pin goes, and using a smooth lining rather than by any product.
And the honest limit: if the flaking is thick and yellow, if the scalp is sore rather than itchy, or if hair is coming out in patches, no shampoo is the answer. Go to a doctor. We say this several times a week and we mean it every time.