Before:
Pick a mental area you want to work on today. It might be positive self-talk, breathing, intensity, keywords, the list goes on.
During:
Periodically during practice, remind yourself to focus on that mental area and see how it might help you.
After:
Did today's MindRep help you? How did today's MindRep help you? Do you want to own it and make it a consistent part of your training?