Seppuku.
My most recent sticking point has been with making out. They might be okay with touch but when I go for the kiss they back off. Then of course kissing her neck, ear or any other part becomes difficult.
Then, I read your post about your escalation process and it dawn on me that I should attempt to go for the make out until the end [almost]
You probably didn't build enough tension. She's not ready. Don't kiss her yet! Take your time! Build tension. Play with her!
To give you an idea, it's something like this:
You're side by side with her. She's fine with your touch? Ask her a few questions as part of your deep diving. And while she's speaking, you play with her hair - keeping a neutral expression, or maybe a slight, slow smile. Then stop playing with her hair, and proceed with conversation. Chit chat, then ask another question. Briefly but slowly caress her bare skin with the tip of your finger - depending on what clothes she wears, could be her arms, her legs, her neck, her belly. Stop. Resume conversation. Later, you draw your lips close to her face, but stop short of kissing, then smile... and withdraw. Later, you can venture your fingers a little more daringly, for instance across her nipple, and wrap it with a sexy comment "Oh my God! There's a lot of people in here!" Another thing you can try is to take her hand, then gently put her finger in your mouth and lick it. If done sensually that will make her pretty horny! She will give you her other fingers to lick one by one! Etc... If at any point she has a reaction to put your hand away or similar, you just withdraw, smile, and gently start again a few minutes later.
It's a form of fractionation I think. I like playing like this, if I feel she's not fully ready for the next step. I like the idea of keeping her logical mind busy with my questions while at the same time being completely comfortable around her body and taking my time to appreciate it. A key element is to do all that with zero nervousness.
Also, when you start kissing, you can start with something else than her lips. Try a kiss in her neck! then go up and gently lick the lobe of her ear... You see, you have so many options other than making out! Only go for the make out kiss when she can't hold it anymore.
Seppuku