Writing Advice
Character Mannerisms/Quirks
Characters play a huge role in story-telling, and without solid-based characters, the reader cannot be as invested into the story.
One thing that makes characters seem more real, are their mannerisms or tics. Basically, a habit that the character does at specific times.
i.e. scratching nose, twisting earring, cracking knuckles
The mannerisms are unique to each character, which provides depth and such.
A list of mannerisms: http://www.jacibyrne.com/2013/06/19/a-list-of-mannerisms-for-writers/