Just moved into a new block of flats for college, and I bumped into the girl living across the hall. We got to talking and flirting, she said I should take the elevator with her when I was about to take the stairs, and then when we went our separate ways she said I should call on her again sometime.

Now i've only recently got my act together in terms of image and some semblance of social ability, hence i'm inexperienced. Tips are needed for original and/or legitimate reasons to knock on her door and not simply ask to see her; I want to casually approach again before I initiate anything.

Thanks!