I really do like eyeliner. I like the soft tip pencils and the liquid liners. I've recently started using my liners in more then just above my lash line. I can give my eyes a really dramatic look by applying my liner to the inner rim of my upper and lower lashes. Here's a small tip though: if you are going to apply liner, you should always start on the outside corners and work your way inwards.
The one thing bad about eyeliner is it can get a little time consuming. You really do have to be careful so as not to make mistakes, and using it every day really isn't appropriate. So what I've started to do is just use my eye shadow colors as my eyeliner. My favorite color is a deep purple that almost looks brown/black once applied. Using it as liner on my upper lid gives me a very subtle, smokey look that appears effortless (see picture below, and no, that is not me). I also like to use a lighter shadow (often with a bit of shimmer to it) under my lower lashes to help open my eyes and make them appear brighter.
What are your favorite eye shadow tips?