How do apply eyeliner under my eye?

Whenever i try to put pencil eyeliner under my eye, it looks like i have dark circles or mymake-up smudged. I also have liquid eyeliner, but of course i couldn't use it. I have gel liner as well and i haven't tried it yet, but what brand of eyeliner do i use, what type of eyeliner (pencil, gel liner, etc.), and how to apply it underneath my eye. Thanks so much!