For the problem of Dandruff, before you wash your hair, put some coconut oil on your scalp and leave it for 15 - 30 minutes...then wash
Try to comb the hair after applying the oil on the scalp so that the hair strands get the oil also
if your scalp /hair is not oily and the weather is not humid/hot it’s better not to wash your hair too often...twice a week is enough