Need help with 'flat' hairline.

Ok I used to have the exact same problem as you a few months ago. Its because I've had the same side part for a few years so my hair naturally falls that way. Then I realized I could essentially "train" my hair to look more voluminous even though its fairly fine. I just stopped parting my hair. I alternate swinging it all to either one side or the other. Looks a bit silly in the beginning when your hair tries to fall into its natural part but eventually you can train it to just swing over to the other side kind of editorial covergirl type. Increases the volume at the top of your head and personally makes me feel pretty sexy!

TLDR: get rid of your natural hair part

/r/HaircareScience Thread