The first things i want to go over are factors that suround makeing a eyeball look good one of the firs thing is always going to be size and position as a general rule the eyes should be about 1 eye width apart as you can seee from this pic ! other considerations are when using egagerated width to show inteligence or un intelligence , this is a factor with pupil size too thing lik e anime character cartoons etc think your character through before deciding !