I kind of disagree with this. I've had best friends whom was confused by all these 'signs' their guy friends have given, and it turns out that the guy was just flirting for fun.

It's good if you want to do this to her, but don't keep her guessing/confused for too long. She'll assume you're just playing around and will ignore it because she don't want to 'perasan' or anything.

Eventually, you will have to tell her that you like her anyway.