When building models it is useful to spend some time finding out what you already know about the problem. Things you yet don't know you know. This kind of knowledge will greatly simplify the model.

I see newcomers making this mistake very often. In industrial vision, for example, the newcomers like to create very complicated models. I then show them that the "box" you trained a entire model to recognize will actually always be there in this position for the camera, because it sits in a conveyor belt which restricts its lateral movement. The problem can simply be solved with simple image processing. Stuff like that happens all the time.