Long hair looks much more elegant when swept over one shoulder, like Kristen Stewart displays. To anchor your mane to one side, twist back a section of hair behind your ear and secure with pins before misting with hairspray.
Heidi Klum in Roland Mouret - 2013 Creative Arts Emmy Awards
It's hard to keep an undercut feminine.
Side-braid of Kristen Stewart
Le "one shoulder", c'est quoi ?