I would say this is mixing two things which shouls not be entangled. As guys above mebtioned, do not punish good behaviour. If you still have hard time reading subtext of what women do or say, be especially careful. Because she may ask you a question because she is interested in you (the interest being communicated on the sub level), on the surface level you understand at as a bad behaviour, so you "punish" it. This happened to me couple of times and it sucks when you realize it afterwards.
For unpredictability, just say yes to things you'd normally say no. Or for example.. I don't like cakes. I think that some are pretty disgusting even. But there were occassions where I actually had a bite because the cake did not seem that bad.
Being unpredictable is also more about her "figure you out". And to be fair, it is not a biggie if she figures you out in some departments. Like how would you react if someone was really up close in your face or disrespecting you. If she knew you do not let anyone disrespect you in a major way, it does bot mean you're "predictable" in the PUA sense. On the other hand if she thinks you're a cute puppy, then some big dude comes along, tries to amog you and you do not back down, stand your ground or even put him in his place, she will be genuinly surprised and her respect will go up.
Lastly, when you reward good behaviour or punish bad one, you need to calibrate properly. It is easier said than done. But it is an important element.