People that don't "get" procurement - Advice to get them on board

Everyday I speak with people that don't understand what procurement can do or think that having done 1 tender process, they are experts in tenders now. So seeing as we all suffer the same fate of everybody being an expert in procurement (except us): In your experience, what has worked for you and your organisation? (Selling procurement internally to your colleagues and getting them to believe in the process and to seek advice from Procurement at the earliest stages?)