The simplest way to get rid of a cowlick is to comb the hair in the opposite direction while it is wet, blow dry it for a few seconds, flip it back and blow dry it again while combing it. Other options include applying hair product.
Cowlicks tend to be genetic, and they begin at the hair's roots. Light-hold serums often temporarily restrain cowlicks when applied close to the scalp. Use a flat iron to straighten the cowlick, working in stages by applying the tool to small portions of the cowlick. Another technique to tame cowlicks is to wear nylons on your head while you sleep.