Because there are so many places/ways to create entities, I think it is difficult to provide a simple, one-size-fits-all suggestion. But here are some ideas (some already possible, some not).
In Table View, perhaps it would be useful to have the cells for mandatory fields highlighted in a different colour if they are empty.
If an entity is created from a list or board view, perhaps cards could be coloured differently when they are missing required field data. Unfortunately, this is probably something that is less apparent to the creator at the time of creation.
Overall, since there is no overall concept of a use ‘confirming’ that he/she has finished creating the entity, it is effectively impossible to prevent them from doing a half-job of it.
Perhaps having a form view will correct this.
If you take the question from the other direction, who suffers from the absence of information? Is there any way to make this pain visible/apparent to the creators?
If not, I suspect users will often want to take the lazy option(!)
Maybe you want automatic, scheduled notifications (email, slack, Fibery) to a user that has created an entity that is missing required data?
“Yesterday, you reported this bug, but you didn’t provide enough detail”
Or could the entity be automatically assigned to the creator until all required fields are filled in?
I’m interested to hear what other folks in the community think…