There is debate in the PUA community as to whether to call or text. My strategy is to do both, and use the advantages of each one. When I first get a girl's number, I send her a text. This text tests whether she is actually interested in me or not. If she answers, then it is a green light to pursue her. If she doesn't answer, then she might have given me her number by mistake, or under duress, or it could be a fake. After I get the green light, I continue to text her. I go back and forth numerous times until I feel I have built comfort with her. At this point, I text her asking if she wants to talk over the phone. Talking on the phone is much more rich and varied than texting. Plus I want to get to know her as much as I can before out first date. After 10 or 20 minutes of phone conversation, I hang up and text her asking for a first date. From there I usually stick to a habit of 80% texting 20% phone call. And I am sure to call girls who do not answer my texts. I usually am able to get them on the phone even if I did not get them with my texts.