Facial Hair: IF they can do it, they have big bushy beards, perhaps to prove they have some testosterone.
Dressing Like a Lumberjack. Same reason.
Hanging around in Coffee Shops and buying the most obscure coffee that can be bought and secretly despising people who don't.
They Think They can Play Acoustic Instruments but Generally Have No Such Talent.
Pretending to Be Nature Boys.
Carrying Backpacks Everywhere.
Absolutely Denying That They Are a Hipster.