Lipliner is completely outdated. Unfortunately far too many people who still cling to it usually end up looking like a throwback to the 80s or a washed up Playmate.
I haven't used lip liner since I was in high school, which was ten years ago, and I shouldn't have been wearing it then! But then again, my makeup skills aren't what they should be. I don't wear lipstick either, I can't stand it, just lip gloss.
I've only used it for turbo-formal events where I had to look really "done"... hate it when girls pick liner a shade too dark and wear it every day, brr.
Very rarely. Only if I'm going out at night and wearing a bold lipstick. Just to keep the lipstick from bleeding. Normally I prefer a more natural look with just a little clear or pink gloss.
I always where liner when I wear lipstick. I guess I am in the minority! It helps define my lips and makes them look bigger. I like my liner just ever-so-slightly darker than my lipstick, but most people probably can't tell. I do liner, then lipstick, blot, re-line, then a little gloss.