I had a client with very mature skin and, as we were chatting, she announced that she had never learned how to put on eyeliner. While some people skip this step, eyeliner is one of my top three makeup products because it makes your eyes look larger and more defined, and makes lashes look thicker. In my opinion, the trifecta of eyeliner, mascara and brows negates the need for other eye makeup (or really any other makeup at all). When it comes to eyeliner, practice a little bit to see if you prefer to apply liner in pencil form or with a brush. I feel I have better control with a pencil, but even so, I use a small brush to smudge the liner into my lash line afterwards. My go-to for this is the Smashbox 20, but an excellent duplicate at an even better price ($3!) is the e.l.f. Studio Concealer Brush, available here.
If you have better control with a bush, you have quite a few options for liner: you can grab the pigment from a pencil, use a gel or liquid liner, or use a powder liner (or even an eye shadow). My favorite liner brush is a run-of-the-mill angle brush:
To apply, either with a pencil or bush, I use small dashes from the outside corner of my eye to the middle, then go from the inside corner of my eye to the middle. Then I connect everything either with the smudge brush if using a pencil, or, if using a brush, I go back over the line a few times to smoothe everything out.
For a wonderful, all-inclusive tutorial, check out the video below. Happy lining!