I always went with "light and cheerful"- full of positive energy. Dating is supposed to be FUN, right?
I agree with you about not giving out your number too soon. I conversed with prospective dates by email or chat for a while then when they asked me for my number - I made the first phone call while blocking my number. You can tell a lot when you speak to someone on the phone. Only after a couple of such calls did I give out my number - when I felt comfortable and sometimes not until after we had met.
When I went on a first "coffee" date - I did not park right in front of the establishment. I did not want them to see my car, my licence plate or to be able to follow me if possible.