I recommend the brush liner.

I recommend the Innisfree Powerproof Brush Liner. I was always stressed because eyeliner would smudge all the way under my eyes, but I bought this because the reviews said it really doesn't smudge, and it really does smudge less than others.

I guess it doesn't work on my eyes at all. Still, I like this one because it sets better than other products. Since it's a brush pen, it's great for drawing a thin tail with a quick stroke.