Have you returned home late and do not have the time or energy to wash your hair, although it somewhat seems unclean? Or maybe you have time and you can't just bother yourself.
Here's a trick to enjoy a new day of fresh-looking hair: Just change the difference.
Hairdressers say you can cover up hair that looks somewhat unclean by switching the difference from the center to the side - or vice versa.
Although this will not make your hair cleaner, it will make it look more fresh again.
Alternatively, you can try re-combing the hair back to add more density to your hair and then comb it lightly again to prevent it from looking too messy.
If your hair looks dull and flat, try to give it a boost by spraying a little water with a spray bottle, then applying some comb to spray the hair and dry it with air.