Texting advice?

Last week I texted a girl I haven't texted in almost a year. She responded and we had a nice long conversation. I asked to meet up and we did on Monday. We had a great time and she was laughing most of the time and opening up about herself quite extensively. At the end of our rendezvous we agreed to make plans to see each other again. I didn't text her on Tuesday but I texted her Wednesday with an inside joke that was made during our rendezvous. She responded excitedly, albeit a couple hours later but that didn't bother me, but didn't reply to the next text I sent her a few minutes later. I let that go and tried again on Friday asking her for a favor my friend asked me to ask of her. She didn't reply at all.

So my question is what to do in this situation. I don't want to seem too needy or paranoid, but I do want to keep talking to her and see her again soon. She said during our rendezvous that she had a lot of free time now, so I assume she isn't that busy. I don't want to screw up my relationship with this girl by seeming clingy, but I don't want her interest to die down from lack of communication either. She gave me her Skype name, but I didn't add her as a contact or call her. So should I try Skype, or text, or calling her? When should I do it? What should I say?

Thanks!