Then you second guess yourself the minute they walk out the door after you take a breath..
The problem I have is taking the 'liability' if you can call it that, of being the one who has to determine an obviously tough shade. 2 people can look at the same Pt and one says a3.5, the other says c3. Whether it matches all comes down to when its seated and we dont have that luxury. Ive held crowns up and had the pt approve, many times, only to have it come back.
The real shade check should be at the try-in, and most Drs arent willing to go through that process, yet expect perfect results in 1 shot. This job.
Another thing to mention is having a system in place so that Drs arent just punting, but are still invested in the outcome.. I make sure that they give me at least their best guess, the closest range, pics!, something to get the case started so I have an actual crown to compare and adjust when I see them, often if its a tough shade or a central I end up having to see them 2x to start the case and check the final glaze..