What is your definition of "sophisticated"?

So my bf and I were having a discussion about style last night and we came to the conclusion that we both dress like bums. Jeans and tees and sneakers every day. Of course we don't shop in the same department but you know what I mean. Then we tried to brainstorm about what we would look like if we wanted to be sophisticated and didn't come up with much. I guess this means we couldn't look sophisticated even if we tried. So my question is if you were to give my boyfriend and I a makeover, how would you make us look sophisticated? What would you describe as a sophisticated style for people in their late 20's and early 30's?

Also we couldn't figure out if sophisticated ladies wear socks. Do they wear socks or just pantyhose?