After trying out tons of different liners, I've found that the easiest ones to apply are the marker-esque versions. If you can color with a magic marker, then trust me--you can apply liquid eyeliner in marker form with ease.
Once I figured that out, I found my very first fave liquid liner: LORAC's Front of the Line Pro Liquid Eyeliner. It applies like a dream, never dries out, and is super easy to apply. At $26, it always seemed completely worth it, since it saved me tons of time and effort. Honestly, I still love it and always have one in my makeup bag.
That said, I recently found a product that is basically identical to it for a mere $6.99! Jesse's Girl has an amazing Liquid Eyeliner that seriously seems to be almost exactly the same as its pricier competition.
I've tried both, and they really do work quite similarly, at least as far as I'm concerned.
My advice? Save the $20 and go with the drugstore liner this time around. Then you'll even have some cash left over to stock up on other fun makeup products! Win-win!
Happy shopping!