I think some of it depends on your age group as well.
For the first date, usually text msg is sufficient. It gives her time to contemplate on it, and you KNOW she's got it in the end. Be specific about what date, time, activity, you want her to join you with. Don't leave it open - women like men with confidence and planning/leadership skills knowing they had thought through things before asking them out.
I would never call on the phone for the first date - especially the younger generation (35 and below - I am old sh!t), talking on the phone is like getting the black plague seems like.
The thing is, if you call on the phone, she has the CHOICE to not pick up the call - this allows her room to play you and game you. WORST thing you can do is leave a voice mail, then the control is in her court. You will be the one ending up becoming AFC if she doesn't respond in the time frame you had hoped. NEVER leave a voice mail... only on your mother's answering machine are you allowed.
After the first date (and it went well, that is) - I would maybe use the phone to keep up the momentum IN BETWEEN the dates if it goes for many days before you see her, to keep her thinking of you but keep the conversation short and sweet. I would use the phone then to ask her on a 2ND date, because you probably want her to factor in making a somewhat joint decision on what that 2nd date looks like and get her input. Most women appreciate that.
Good luck.
Exodus