I have generally used 3 things with my son in the past.
1. Game time examples from other games
2. Game time examples from his game.
3. Make up other examples/situations using 1 & 2
-also my son watches more ESPN gameday than any other person I know.
This helped out tremendously...
Ive generally tell my players to think of the 4-5 most likely outcomes of the play involving THEM! I find this makes it easier to limit the thinking each player must do.
ie: 2nd baseman with runner on first.
soft hit grounder to the left or right of player
hard hit grounder to the left or right of player
ball hit to left side of infield
bunt to first
ball hit to left field
ball hit to right field
and then he MUST have already thought out what he must do in each situation before the ball is hit. This way he will not pause to think about what he must do. This does 2 things, help him make a decision quickly and increase his confidence for the next play.
it is very difficult to write down every example, for every player, in every situation.
i generally spent 15-20 minutes during practice breaking down the positions, each side of the infield, then pitcher and catcher, then outfield...