What are the different techniques for building attraction?

So after you open a girl and maybe give her a compliment, you don't want to just ask for her number do you? Or are there situations where that's okay to do? I've heard that if you don't build attraction first you will have higher rates of flaking. But I'm not sure what to say or do after opening to build attraction. What are the different techniques for building attraction? What comes after the opener?