When I was in high school I sang in a jazz choir (you might be thinking this sounds lame, but it was cool, trust me). It was a small choir so there were a lot of opportunities to sing solos. I sang things like Duke Ellington and Paul Francis Webster's, I Got it Bad (and That Ain't Good), and Jerome Kern and Oscar Hammerstein's, Can't Help Lovin Dat Man. They were gorgeous, emotional songs, but they were kind of a stretch for a sixteen-year-old who'd never had a boyfriend, never been in love, and didn't use words like "ain't" or "dat" in regular conversation.
I strived to have an emotional connection with the audience (kind of like writing), so I worked hard to feel the words I sang. Since I couldn't draw on experiences from my own life I often borrowed emotion from books, movies, songs, or the lives of friends.
I find that I do the same thing when I write. We've all heard the advice to "write what you know," and I think it's good advice, but I think we can sometimes "know" without experiencing things first hand.
Most of the characters in one of my WIPs live lives that are nothing like what I know, but I've been able to draw on many other sources (books mostly, but also movies and even music) to make them feel real--at least to me.
Do you ever write what you don't know? How do you make the characters, setting, and plot feel authentic?