Give them a sheet with the titles of the seven wastes on it.
Draw a circle on the floor with a piece of chalk (or simply make a spot it that’s not practical)
Ask them to turn off mobile phones and radios
Then ask them to ‘stand in the circle’ for 10 minutes and observe the operation, looking for examples of each of the wastes. get them to write down what they see.
Then ask them to come and explain what they have seen. Once they have done this, ask them to fix just one!
Keep repeating this over a few weeks, this will start to condition individuals to look at their areas in a different way. It’s amazing how much they will see.
Simple but effective