I have always had very fine, baby soft hair and in the two or three years pre covid it had become suddenly even more so.
I used the first lockdown to stop washing it so often (used to be every other day) and now only wash it once every ten daysor so. Also, it having grown a lot with lack of access to a hairdresser, it now gets brushed only twice a day. Once to put it up in the morning and once to plait it before bed.
Like a previous poster, I don't use a towel but wrap it in a clean t-sirt after washing and let it dry naturally. I will never have a really thick head of hair, I don't have the genes, but can honestly say, at 61, my hair is as thick as it was when I was a teenager.