well whatever you talked about in person try transitioning from that.
The general rule of thumb for phone is its a comfort building tool. The main thing a woman is looking for is an awkward pause, as if your awkward on the phone why should she want to talk to you?
When your first talking on the phone, it should be 90/10 talking just to keep things going.
In my game I reach my hook point and seed a conversational point, such as one routine I do is use the cube, I then say "I'll call you and tell you what it means on the phone" and take it from there.
If I don't do this I exploit commonalities, and launch into comfort building. Just find something that you two have (could be a personality trait etc...) and go from there, keep it funny and easy going.
Hope this helps
The_Musterion