Select Challenge mode and pick match play (doesn't work with tournaments). When it is your turn press select and start to give up. Keep doing this for 3 matches and lose. You will get loyalty points even when you lose the match. Keep doing this to max out all the chatacter's loyalty.
This trick allows you to get a free power shot: when doing a power shot, set the power and impact as you normally would, but the moment the club hits the ball (after setting the shot impact), press triangle. If this is timed perfectly, the power shot you are using won't decrease the number of power shots remaining. This does not affect the shot at all, and it doesn't have any negative consequences if done incorrectly. This must be used during a power shot or it won't work.
In order to get medals in your Medal Gallery, perform the following tasks:
To be able to get the new caddies, perform the following task:
Enter the following code as your name when you start a new game.
Defeat any of these characters in a VS match in Challenge Mode to Unlock them