Been lurking around Seddit for awhile and I've noticed one thing: all the stories of success and advice given is in regards to new people. People that you met clubbing or at the bar etc. Does anyone have advice on how to escalate a relationship with someone you already know?

Some context for my particular position is that one of my friends who I've known for a while kinda faded out of contact for a little over a year, and now we've been talking a bit more. We've hung out with some friends since then and I'm really liking hanging around/talking with her. I want to escalate this relationship so any thoughts?