Sure, it's a confidence boost sometimes if I catch a guy checking me out--If he's not doing it in a creepy way. But I don't like being approached when I'm out shopping or walking around though because I'm most likely on a mission to get things done and I don't like being interrupted. That sounds bitchy, I know. If it's a quick compliment or something, sure, fine. But I've had guys try to stop me to talk while I'm walking by and I'm not sure how I look even look approachable in the first place when I'm walking fast, looking straight ahead, and probably with my resting bitch face on. I guess there's a time and a place to approach people, and you kinda gotta judge if someone is willing to be approached, you know? I'm sure that's hard sometimes though.
Depends. Don't stare cuz you'd look like a creep and don't follow cuz then you're acting like a creep. can occasionally look over, maybe try to get near their line of sight then look over but not too hard. Just peaks until the person notices then like hold the eye contact for 2 seconds. If she's interested then she'll start to sneak leaks at you. If you guys continually do that, say it happens 3 times to be sure, then its safe to walk over and talk.
It might seem like it'll take a while but you have to be sure first and so you don't get embarrassed. Girls notice when they someone who is attractive to them looks at them so don't think you won't get seen