Well, this is exactly one of those things where all the routines and PUA stuff is totally useless. It will come to you gradually with experience. Just chill out and don't act like you've been waiting for the moment to come. Stock your fridge with some drinks - whatever you feel appropriate (wine, beer, whatever... you might also want to make her a mojito or cuba libre). Talk to her for a while, show her some cool things in your apartment. For example I play the guitar (both electric and acoustic), so I like to play a couple of songs for the girls. It will play out somehow, don't plan it too much. If you sense that she's horny, you might do her right off the bat. If not, don't worry and watch the movie first.
The most important thing to remember: This is not something extraordinary. Just a chick coming to your place. So relax
Good luck and have fun.