The complexity of phonegame is sometimes widely underestimated. Here are some pointers.
The do's:
Send short texts, maximum 324 characters. Even when you use SPAM. Simply increase the frequency then, but never send long texts. Keep it short.
Be nice, use smileys and winks a lot. But at the same time try to be cocky funny.
Be casual. Don't get overly romantic or eager. Not even a little bit. This will blow you out.
Use the "three strikes your out" rule. If you send 3 texts (or for instance 2 texts and one unanswered phone call) move to the next girl. This will force you to go out to hunt for new numbers and gives you confidence over time.
Try to put some role play into the pick up. (like your the bodyguard an she is the actress) This way, when you #close, you can begin and end your text with the role playing titles. Like: "Hi Pamela Anderson, are you keeping the beach safe today? Just ring me when these annoying guys are bothering you again.
X. Your bodyguard 
"Preferably use texts to set up a next meet or even a phone call. Calling unannounced only works when you have sufficient rapport and the chick is not too young. Try to avoid calling out of the blue.
The don'ts:
Never send a text after a text within the hour. Wait at least 5 hours!
If she texts you back, don't immediately text her back. Unless it is in the evening and it's clear she wants a response fast. (usually a question, or something like "goodnight" in it around 10 or 11 in the evening).
NEVER TEXT, UNTIL YOU HAVE FIND SOMETHING THAT WILL MAKE HER SMILE WHEN SHE RECEIVES IT!!! EVEN IF IT TAKES YOU TEN WEEKS TO THINK OF SOMETHING CREATIVE!!!
Never get angry, or whiny on the texts or over the phone. Keep every interaction, short, fun, attractive and targeted on increasing rapport.
Learn to "feel" when to propose a meet-up. Usually let her give some text IOI's and after 3 pleasant texts that were returned, start talking about the next time you could spend some time together. IF YOU START DOING THIS ON THE FIRST TEXT YOU WILL CREEP HER OUT!!!
So, these were the do's and don'ts. The most important ones though. I tell you this. I always notice girls are punching their digital keyboards on their iPhones a lot faster then guys. So with many thing within the PU spectrum, they are usually further ahead then us when it comes to phone game. And they are super-sensitive. This means they can pick up on your insecurities in just a text of a 100 characters. The do's and don'ts will give you some advantages though.
Another thing I would like to tell you is: PRACTICE, PRACTICE, PRACTICE. Get as many numbers as you can. Even if you thing the girl is not interested. You will learn you can even build attraction that wasn't there yet by sending brilliant texts. BUt this takes you a lot of practice. On a good week I can be texting an e-mailing 5 girls at a time. When you are in this mode you will learn fast.
I used to hate texting. It thought it was a part of womens defense mechanisms to keep distance. It is off course that, and that is probably how you are feeling about it right now. But if you keep practicing, you will find it is actually a really cool and handy way of getting to an emotional connection.