I drew up a list of priorities, both for the results (looks, function, etc.) and the logistics (US, cost, etc.) and ranked both in terms of what I cared about most. It turned out that a) I did not want to go overseas and b) my preferences for the looks matched what North American doctors were doing, so that was one question answered immediately. Then I ruled out any North American doctors who were either too far away or had *really* consistently terrible reviews. I looked at the results coming from several of the big names, and picked the ones whose outcomes seemed to most closely and reliably match what I wanted (in my case, I cared most about sensation/function, then looks, then depth). There were two at that point who were both in line with what I wanted and reasonably priced, but one had a BMI limitation, so that was out.
I'm happy to tell you which doctor I went with if you want to know, but it's not relevant to the question of how to pick one - your priorities might be different from mine.