Along with staring, never do it for more than 4-5 seconds, as this bypasses the comfort zone. It works best if accompanied by a little nod at these points of inflection. When I pass girls, I stop them by excusing myself and asking them if they like a certain type of music. This is just one example of how to approach a girl. I wouldn't recommend using it because things have to be spontaneous for girls to take them genuinely.
Pupil size is very important in attraction.
If her blinking is slower, it means she's relaxed and at ease, so she's in a good position to be swooned by you. If her blinking is long and slow-moving, she may be seductively trying to grab your interest. When you make initial eye-contact, and if she looks down then away, that's interest. If she just looks away or gawks back glazily, it doesn't mean anything. But don't stop trying.