I find it's good to send an email first to introduce myself but I only do this because I have good feedback and I've completed my profile..... so I may send something like this:
Great profile and love the pictures..(or some sort of intro)
I'm very interested in meeting you and making a booking soon.
Please would you have a look at my profile, feedback and field reports, then if you would like to meet get back to me asap (with your phone number) and I'll give you a call
If a girl doesn't answer a message like this I don't pursue a meeting with her.
It does filter out any suspect girls imo, plus the girl is able to find out about me... My age, what I like, who I've seen and what they thought.
One Note: I will never see a girl unless I've spoken to her on the phone first.
If you don't want to email, I can't see the point of a text as a call will need to be made anyway. So in answer to the question, a phone call is ultimately the best way of contact....
It's worked well for me over the years