PUCKER UP SWEETHEART
First, touch her casually, and see how she responds. More than likely, she will have no visible response at all. If she pulls away at all, keep your touching extremely brief, and keep up your romantic conversations. If she continuously shrugs away from your touch, consider getting rid of her and moving on. If she does respond positively, touch her for longer periods of time. If she gets more relaxed and animated, if her skin flushes, or her eyes get shiny and reflective, these are all signs of positive response. If she responds positively, move to putting your hand on hers for longer periods. Don't make a big deal of this, just let it seem to happen.
The Hug Test
The first rule of hugging a woman is that you keep it short. Use it as a test of her readiness, not as a chance to get your sexual or touch needs met. When saying hello or goodbye to her, you can often simply take her in your arms and hug her. If you keep it short, it won't scare her, and you'll be able to gauge her response. Does she press into you? Does she seem to want to really hang on? That's a good sign, and you might want to move to kissing her right then. If she seems to want to get away, then you know you have more work to do in making her feel romantic feelings.
The Face Kiss Test
Along with hugging, you can try face-kissing. This is when you kiss her cheek, to see how she responds. If she leans into the kiss, and smiles, she's into it, and will be receptive to your lip-kiss later. If she pulls back, or winces, then it's back to the drawing board. She most certainly won't be receptive to a lip-kiss if she won't take one on the cheek willingly.
You can also gauge a woman's level of interest by her level of enthusiasm. Her enthusiasm will be shown in her overall demeanor, but it's best shown in the time between one activity and the next. It's between the activities that you do together, rather than during them, that she has the best opportunity to claim she is tired and needs to go home. Between activities, watch her level of interest. After the movie, is she eager to go out for coffee or a drink, or does she seem reluctant? Does she seem to be looking for a juncture at which she can end the date, or is she up for partying with you all night long? It's these between spaces that will tell you her level of interest.
Pretend Kiss Test
This test also primes the woman for your kiss. You begin by moving towards her, as if to kiss her, at some point "change your mind," and back off again. If, as you move toward her, she backs away, she probably doesn't want to kiss you. If she stays still, or moves slightly forward, she's probably interested. The pretend kiss can "seal the deal" for the kiss later. If she hasn't moved away, then you both have acknowledged that a kiss is inevitable, and it's only a matter of time.