While I haven't done the gaze itself to a female where one looks from one eye to the next before glancing at the lips, I tried this on myself. Not in the mirror because there's a sort of distance between it where it's not good enough. So I resorted to my camera and was about three feet apart, That's usual talking distance between people before growing slightly closer.

You can see the small change in focus but the most abundant is when you look downward. It's blatant to the other person and for women, they'll notice it. I couldn't tell if I was looking at my lips or even downward at their body. You're pretty much checking her out without shame(This is key right here. Don't be embarrassed. Be a man!) and if she's receptive to this, you're in the clear to go in, kiss and proceed to ramp up attraction.

It may sound stupid or obvious but after seeing it first hand, it's a big compliment and an IOI viewer to the woman you're gaming. Long as you're not looking like a serial killer, you're fine.