Visualization is a mental preparation exercise that can be used effectively in sports for kids and adults. Players (and parents, if you wish), please spend 5 minutes watching these 2 videos:
This 4-minute video explains it:
https://www.youtube.com/watch?v=pNsK_MyB-UY
This 1-minute video of Coach's Corner shows an NHL player using it before a game:
https://www.youtube.com/watch?v=_AH2NhZhJRo
Warren