I wouldn't treat a romantic scene any differently than any other scene. I would really say the biggest preparation was chewing gum and breath mints! For a kissing scene, it's all about the breath mints!
I think some people wished I'd kept myself out of the book. But I kind of insist on it because I want the reader to share my engagement with the material, if you like, not pretend that I'm doing it completely intellectually.

