After receiving her phone number, wait at least one night before texting her. This is because texting immediately usually sounds very creepy and is not advised at all. Moreover, it reflects that you are not patient with things at all, which is a turning off factor for most of the women.
Instead, try to show that you are quite patient and can take slow steps in life. These are the little things you do which makes up your first impression in front of the woman. Try to avoid texting too often or immediately in order to let her get hooked on to you.