Other than the obvious name, title, address, and so on, how do you effectively use this space which is in front of your customer's nose?

Do you have a CTA? What is it? Does it work?

What's on the back? Is it blank for notes or a personal message? Is there some kind of mini form you or the contact can fill-in? ("We met at ____, we spoke about ____, we agreed to ___…"

I'm meeting with my designer next week to get my cards sorted and I thought it would ask you what has worked for you (or even failures, we can all learn a lot from those!).