it depends,
the best way(as ive found) is to arrange you and some of your social circle (maybe 2 other guys and 3 other girls) to go out somewhere, then maybe the day or two before, send the target girl a txt or call saying, something like "Hey, im going out with some of my friends this (day), i think you'd love them. you should totally come!" somthing similar to that.
if you just want to go with jus tthe two of you - send her a text or call her and say somthing like " hey! i was thinking about going out for some (coffee, specific dinner, specific lunch, et c.) at (place where you'll get it) you should come with me" the reason you say what you're getting and where you're going, is that you are trying to make her picture being there, tasting the food, smelling the aroma, with you. this will increase your chances of her saying yes 10 fold.
also , you need to do some planning ahead of time. well... less planning asn time bridge building. basically when you first meet her, and get her number, you have to leave some threads open, so that at the end of the convorsation, you can say "we have a lot to talk about" (not in a bad way lol) this will make her WANT to see you again.
one last thing, i perfer NOT to text, and this thread has my explaination why, although with the second instance (going with just her) texting may be better. heres the link anyway
doesent-text-me-vt53819.html?highlight=
happy gaming!