At a bar
“We should hang out some time soon”
He fancies you (a lot), but he’s unsure of how you feel and he’s testing the waters. If you like him, then make it clear; otherwise this could end up being a missed opportunity!
“Let me give you my number”
By giving you his number he’s expressing interest, while taking the pressure off of himself because he’s leaving it up to you to get in touch. There’s a touch of arrogance about this statement, as he’s presuming you like him and want to see him again.
“Do you come to this place often?”
He’s trying to engage you in conversation – plus work out if he would bump into you again if he came back. He could also be trying to work out if you live in the area…
"Excuse me, is this seat taken?"
This little phrase is innocent, charming AND polite. It's an effective pick-up line because he's showing consideration for the fact you might be with someone, whilst showing interest.