I'm gaining confidence in my approach and closing skills. However my sticking point is I have trouble maintaining FB relationships. I suspect I haven't adjusted my game to the new rules and comfort level after we hook up.

How do you get to a comfort level where for the first time with a girl you know you can text something like "you free? come to my place"? How do you know when you're cool to do that? Or do you not 'know' and just try it? How do you initiate? Or is it better to wait for girls to initiate? How do you establish that it's an FB relationship without getting too serious? How long before a get-together do you set something up? A day? An hour? 3 days? Or how do you tell what's going to work for a particular girl? Do you set up to do something more innocent like get drinks and then work attraction and escalation or do you just make it explicit and say "get over here"? I know there are different setups, but how do you know where you are?

I'm just looking for general good materials on navigating this area, because I think it's under-covered. Anyone have good links or pointers to other material?

TL;DR How do things change after the first hook-up and what do you do differently to keep the FB relationship going?