I've noticed one of the things good bb seem to have that most other people dont' (apart from mass of course) is trap/shoulder proportions. I think many, myself included, find it very easy to gain mass in the traps, so much so that they appear disproportionately large compared to your shoulders.
I don't train my traps directly at all, yeet they are still large. My shoulders on the other hand look small in comparison.
Large shoulders look awesome in my opinion, but are hard to get. Large traps on the other hand seem to come to almost anyone who trains.
So how do bb get such proportions. I sit simply a case of being patient, and waiting for your shoulders to cath up so to speak.