It might be cool until people start thinking you're a guy posing as a girl and then it's all downhill from there, or it gets really really weird.

I never understood eyeliner. Base coat on the face I can understand, and lipstick. Maybe even eyelash thickener. But not eyeliner. My mom had her eye lines surgically made permanent, which was huge among Asian women in the 80s and 90s. I can't see the point.