People don't understand the importance of the eye in anime. In traditional anime, the eyes are supposed to convey almost all of the emotion, and the mouth is just a supporting detail. I see people making eyes exactly the same in all their pictures, and only the mouth and eyebrows conveying the emotion. DON'T DO THAT. It seeps the life out of the picture.
Note to @PinkamenaDianePie489: Where did you learn anime? That eye is no anime I've ever seen... I'm not even sure if it IS anime.