Re: Lip Liner
Realizing I'm late on the boat, I just thought I'd add my two cents.
Rule #1 is to use light, feathery strokes. Do NOT try to draw a continuous line around your mouth; you will mess up and it will look ridiculous.
Now, do you want to fill in your entire lip or just the outline? If you want to fill the entire lip, you'll have to do that first. When you put lipstick on top, the color will be altered by the lipliner underneath, so keep that in mind!
If you want to just outline your lips, you can do that before or after you put on your lipstick. I generally prefer to do it before because when the lipstick goes over top of it, it tends to "fade" in to the lipliner perfectly. You can do it after you've applied lipstick as well, however, and if you use a light hand, it can look quite nice!
If colored lipliners make you nervous and you only use lipliner to prevent feathering/smearing, you may want to try out a clear lipliner. I use lipliners for both (to add a 3D effect and to prevent feathering), so sometimes I'll just use the Revlon ColorStay liner, and that works great!
PS: if you wear a liquidy gloss, it's a given that it will probably manage to pull color outside of your liner after a while, even if it's only a little bit. Throw a Q-tip in your makeup bag so you can touch it up easily mid-day!