My writing skills are far superior to my oral skills, so I prefer to write. In the past, I've sent T emails, some rather long. I have also written things and brought them to session, but I actually felt more comfortable reading what I wrote to T. That way, there was no uncomfortable silence and I didn't have to look at her.
I've come a long way since then, and I either come to session with no real agenda or simply make a list of things to bring up to make sure I don't forget anything. I make good eye contact now. That being said, I will still write an occasional email if I want T to know something prior to session.