All it takes is a passing comment to take the wind out of the innovation sail:
1. "If they don't look busy, they are wasting time." Think about it: if employees have no time to ponder or fiddle, they have no time to develop anything new, either.
2. "Remember when we did this? It was adisaster." Nothing kills revolutionary thinking faster than harping on all the reasons something didn't work 10 years ago. The world has changed, and what didn't work then, may be viable now.
3. "She's got some good ideas, but she's so junior." Keep in mind some of the greatest game-changing products and services in modern times were started in dorm rooms and parents' basements.
Spend time training your managers (and possibly readjusting your own thinking) about best practices to shape a business culture that celebrates — rather than stifles — ideation.