I usually avoid kissing on the hands. Now, with that said... I have used it to tease - somewhat.
Almost kissing them on the hands is different and creates an entirely different scenario. Imagine a man who picks up her hand, holds it up to his mouth, nearly touches it with his lips, and pulls her body a bit closer and continues with conversation. Makes those girls giddy with interest once you do so. I'll sometimes use it whenever I feel like she is too comfortable with things and may be in auto-pilot. All of the sudden their auto-pilot breaks and they have no idea how to react, especially if you start up conversation again.
Note on being spontaneous: make sure that the women are the ones who think things are spontaneous, not yourself. It may feel like you spontaneously kissed her, but in reality it was premeditated. She only perceives it as being spontaneous as there were no obvious clues as to it actually happening. It's smart to "spontaneously" kiss a woman when she is running in auto-pilot, but in reality that was a response. It's not smart to spontaneously kiss a woman when you are in the middle of a deep dive.
So, when you are being spontaneous, it really only works when you are planning ahead. She just
thinks it was spontaneous

.
Take her home!