See usually if I lower my arm or tap my fingers my dog will come over to my hand, but if she wants to.  If not, she'll look up pretending like she doesn't know what i know she's thinking.  So i tapped and she didn't want to come over, but then I thought--maybe if i keep tapping my hand enough, it'll annoy her to the point where she'll say fine and she'll come over so i can rub her neck.