I am making two BPMN model validation tools, which reinforce the rules of my Method and Style approach, available on BPMS Watch. As I have said in the past, the biggest obstacle most people - business and IT - face in creating good BPMN is attention to proper model structure and labeling... NOT the shape semantics or fuzzy business logic. The best way to get into the habit of properly structuring and labeling BPMN diagrams is to have an automated tool check your model over and report violations of the rules.