I'm gonna have to condense a lot of info here so you can try to get the bigger picture.

The backstory: I've been friends with this girl for a few years now. We were never super close, but always very friendly. Well, last summer she broke up with her longtime boyfriend. I got together with her to genuinely hang out and catch up as friends. She'd been drinking, and kept offering me booze too (not at a bar). We ended up having crazy sex for a couple hours while we were intoxicated that night. It came out then that she'd had a big crush on me in high school, and I was okay with that considering I find her very attractive. A few days later I text her and ask when she's free to see if she might want to grab coffee or something. She says she's not sure when she'd be free. I managed to set something up with her eventually and we ended up just sort of sitting awkwardly in my kitchen drinking coffee and conversing until I had worked up the nerve to kiss her. We made out a bit, but the situation was still awkward when she left. That was the last time I'd really spent any time with her until recently. I'd run into her at her work (at a local food store) and she'd always greet me with a smile and end the interaction by saying "We should get together sometime, I'll call you when I'm free." She never called. After a couple months she got back together with her previous longtime boyfriend (who apparently had never liked me because he knew about that crush she'd had on me), and our communication even on Facebook dropped to zero.

The recent situation: She broke up with her longtime boyfriend again a few months ago. I ran into her at a show on Halloween. I'd noticed her early in the night, but didn't go over and say hi because I assumed she didn't want much to do with me after all the awkwardness of last year and such. But she came up to me at some point in the night and said hi and we talked for a while. At the end of the night, as she was leaving she said goodbye to me, gave me a hug, and kissed me on the cheek and said we should get together to catch up sometime. Very positive sign in my book, especially with someone who I wouldn't expect it from.

So I text her that Wednesday to see if she would be free for lunch or coffee on Friday (I know she works night shifts). No response at all. Ran into her again at a show the following night and all of our interactions seemed forced and awkward, even though she was just out with her girl friends. I even had to prompt for a hug goodbye.

I wind up running into her again about a week later when I'm out at the bar. I actually just saw her from a distance when I was outside another bar talking to a friend. I didn't want to approach, but my friend was a good winger and got me to walk over to that bar with him. I didn't say anything to her, but as my other friend and I walked out of the bar to leave (knowing she was outside smoking a cig), I made some exaggeratedly loud comments in response to him. She noticed me then and called my name. We talked for a bit, my friend excused himself, and it was good. At the end of the night she said I should call her so we could get together and catch up.

I got really caught up with work and wasn't able to call her until shortly before Thanksgiving. I got voicemail and left a message. She sent a text the next day saying sorry she'd missed my call. I asked her then if she'd be free on that Friday or Saturday night (completely not knowing her availability) to grab drinks and catch up. She said she wasn't and that she'd let me know next time she went out. From the perceived tone of the text and with that message I assumed it was a polite brushoff, but replied with "Okay, cool. That works. :)" anyway.

Having written it off as a loss at this point, I was surprised when I got a message from her Saturday on Facebook saying "hey, I get out of work at 11 tonight so I think I'll be going to [local bar] for some drinks if you wanna meet up". I replied that I'd probably take her up on that. I met up with her, we talked, played some pool and had a generally good time until the bar closed. We failed at finding an afterparty and just parted ways. I didn't want to push my luck that night, so physical contact was limited to 3 hugs (once when I got there, once when I thought I was leaving, and once when we parted ways), and a few high-fives during pool since we were playing on the same team. I'm not a high-five person, she initiated those. We decided at the end of the night (each of us with a head full of about 4 drinks) that we should definitely get together again soon.

I sent her a text on Sunday around 3 to just say I'd had a good time the previous night, thanks for inviting me out, and that I look forward to next time. She responded within 5-10 minutes with "Ditto!"

So this is where I'm at right now. It was a bit of a faulty start, but it's now moving in a good direction. I'm looking for advice on how to continue to advance the situation towards something either more physical or romantic. I'm pretty new to all this. I'm cool with just friendship so even if those options crash and burn, I've managed to rekindle the friendship aspect. For reference, she's really only free at night after 11 unless she's got a day off and I work day shifts. I honestly don't give a damn about going into work on little sleep since I'm a bit of a night owl anyway, so I'm mainly working around her schedule here. Any advice at all is helpful. What have I done wrong in the past, what am I doing right, and what can I do better in the future?