For me, it was collaborative. I had a consultation with Speigel via Skype, where I talked to him about what I thought I wanted done. He just listened quietly. Then he offered his own recommendations, which were essentially in line with my desires. He also recommended that I use the virtualFFS service to get an idea of what I might end up looking like, which I did.
When I went to Boston, I had a longer discussion with him about what exactly he was going to do. And we negotiated a bit on my hairline, because we disagreed a little. In the end we reached a compromise. My sister was also with me, so he decided to base my nose off of hers which was pretty cool. I also gave him a copy of my results from the virtualFFS, so he had a kind of guide to my expectations.
I was really happy with my results. They were definitely better than what I was expecting.
I guess on the whole I felt like... he's the artist, he's the one with experience. So mostly I preferred to defer to that. I think the biggest decision is just picking a surgeon that you are comfortable with and who shares a similar vision of what to do with your face... and then let them do their job.