There's no single working formula. Girls are different and so are the situations and circumstances under which you meet them.
What I'm trying to say is that you could meet a girl tonight and text her tomorrow morning and depending on the girl (and how well you play it) you could still have great success....
Generally its not always that way..
It's not the same texting a girl you met half-drunk at the club saturday night than texting the girl you just met outside starbucks while she was walking her dog this morning...
In my personal opinion, whatever the scenario is, I'd wait at least 2 days before you call or text
If you text her be short, funny, have a purpouse and do not get stuck on one topic. Also remember not to reply her right away...
You want to stablish contact first of all but you dont want to make long txt conversation (remember, you probly have things to do
). You want to have a purpouse, you were not just "thinking of her" (Like you just remembered she still doesnt have your number and you want to make sure she does). You want to be funny but not clownish...By the way. I would call if I wanted to set up a D2....
If you're gonna call, remember the same thing... Funny, keep it short, have a purpouse, listen and pay attention to what she says, have a strong confident voice, Smile (Yes, Smile at the phone
Always suggest a day (do not, please, do not say "When can you do it?, do you have free time?")