I have heard from multiple people that eye contact is essential in letting a girl (or guy, I guess) know you’re interested.
But what is the 411 when it comes to said eye contact? Do you keep looking until she does? Do you then keep staring? Or is like looking at the sun? What’s the deal?
Just smile, like genuinely, and wave or acknowledge her with your head when she looks. And if she turns away then stop, she’s not interested or she’s playing manipulation games. There’s no “right look”, that’s something Hollywood made up for romance movies. The only bad thing you could do is exactly what they do in those movies. Sitting across the room and trying to just use your eyes reads as creepy. So if you’re trying to catch her eye, you should also be trying to get to her, talk to her.