Most Helpful Girl
I think a woman will absolutely make it clear she wants to be kissed. When I went on a date with a guy in the past, he would do something like shake my hand or hug me, and I did one of two things. In a handshake, I pulled his arm to me so I could give him a kiss on the cheek. In a hug, I was already at his cheek and gave him a peck. This way it was clear "I'm kissing you so you can kiss me back". Sometimes if the guy kissed my cheek back right away I knew it should have been a kiss. So instead of worrying about a close, look for signals from her like this or other things that let you know it's okay to do a little more.
Also, touching her lightly in places like her back when you're walking out, or taking a feel of her hair are very simple ways to show you want more and they are also very sweet. It's affection without being smarmy.
Most Helpful Guy
Tell her you're going outside, and see if she'll want to join you without you having to ask.
If she doesn't want to join you without you have to ask, it means one of two things, neither of which is something you want:
1. Large ego, needs to maintain control through power dynamics and power games;
2. Doesn't really have that strong of an interest in you.
I think this is the best way to test for both of those things from a girl. Because, if she doesn't naturally want to join you outside, you were just heading outside anyway, and hey... you're already outside and exited that situation! LOL
Now, if she does want to join you outside, you have to have some "excuse" or "reason" for leaving the bar. "Smoking" is an excellent excuse, and a large reason why smoking has because so popular, but that shouldn't be the only social excuse/reason people can think up of.
The next best thing is, "Hey, it was really loud in there. I'm just going to go grab some coffee from  before I start heading back home. (start slowly walking towards that direction). So, [keep talking]."
Again, same thing... it's just another test. It's a "hanging So." So...
If you see her moving and following you, that's good.
If you don't, stop, tell her it was nice meeting her, and wish her goodnight, then go get some coffee.
As she's following you to get some coffee... you can do more talking than you could back at the bar, and now, you've "left" the routine/standard day-to-day boring life behind, and you're both alone, on this new adventure together - fun.
When you get to the coffee place, immediately offer and ask her what she wants. Treat her, like a gentleman. No, don't roll your eyes. This is not weak-sauce sh*t. This is you showing that when she follows your lead, it's good, it's positive, she gets what she wants... which is a guy catering to her (but she's not going to get that when she doesn't follow your lead). And, she gets it in a safe way (i. e., not him being a gentleman just in exchange for sex).
I definitely would just be "emotionally aware" of her level of "excitement" with you before you commit to closing a certain way. If she's VERY HOT for you and you close by asking for her number, now she's feeling frustrated and angry at you and has lost interest in you. If she's warm, but not HOT for you, give her the pleasure of YOU asking for HER number (it will make her feel wanted, desired, and pursued).