I personally comb my hair right after ishnaan by using a little bit of oil. Some Gursikhs like to make their kesh hare first and then using oil they comb their hair before tying dastar to do ardaas.
It is easier to comb hair while it is still wet and that is why some Gursikh's comb their hair once right after ishnaan and then once while they are about to tie their dastar.
Preetam Singh