it was suggested to me a while back that the way the robe drapes under the neck is screen accurate, but I can't figure out how to do it at all:

And, to be honest, i can't find a single photo of anyone with it looking this good / having it at all!
Any ideas how to get this distinctive flow? My cloak joins with three poppers along the neck line but I'm happy to alter it for this to work.
Thanks