A hipster is someone who goes out of their way to show others that they are different and does so for no other purpose. efficiency and practicality are not considered by the hipster. They want others to think that they are different in some creative or unique way.
Thus there is no set items worn or things said/done.
ex 1: Two people can dress identically, but one person may think he looks good and enjoyed assembling his outfit for his own reasons while the hipster designed his outfit just to be different and to be admired by others for it.
ex 2: Someone may like to drink Pabst Blue Ribbon because it is cheap and tastes decent. but that doesnt make them a hipster. But a hipster will drink Pabst even though they are rich and dont even like the taste, but they want to be admired or recognized for it.
ex 3: A hipster will say "I cant believe Im seeing the Black Keys at the [huge venue] ACC, they used to be so unknown" in a blatant attempt to show off his prior knowledge of the band. While another person could discuss the old Black Keys albums to do a friend a favor and turn him onto some new music.
This is my well considered opinion and Im sticking with it for now.