One of the main reasons why liquid eyeliner is a mainstay in most women's makeup bags is because it does a great job of adding definition to your eyes. It makes your lashes appear darker, which helps to highlight the shape of your peepers, and it can also be applied to make your eyes look bigger. But to get all of these benefits, you have to get to the roots.
Glamour Magazine's beauty blog recommends putting on your liquid eyeliners as close to your lash lines as possible. This will ensure that you're not getting an awkward hovering effect above your fringe. It's best to do this by closing your eye and steadying your hand on something like a vanity or countertop for support. Then, wiggle the applicator back and forth across your lash lines.
This method should help you get right down into the roots of your lashes, making them appear thicker and darker. It also helps to use a pencil eyeliner on your inner rims - being sure not to forget your upper lid. Of course, a generous helping of tube mascara applied near the roots of your fringe will also thicken up your lashes. You can get it down there by wiggling the wand back and forth at the bottom before you swipe upward.