Ensure that everyone is introduced to security-related procedures during the on-boarding period with an e-learning program. After that, select several ways to address security best practices frequently via different ways: a video integrated in your internal intranet e-magazine, posters, sending dilemmas to the mobile device of the employees via an awareness app, confronting employees with security situations via short videos on internal video news-screens, implementing gaming around security, etc. This can be done in a global operating company.
Be sure to support all of these actions with a program for managers (what is the role model, how is security integrated in the communication with employees?): this can be done in short workshops as a start, and followed up by addressing examples of good communication via videos used in the awareness app, for example.