Here’s a list I came up with after many challenging rounds:
Turn off phone / Don’t slide!! / Be patient / Be respectful / Be courteous / Don’t brag / Tell a good joke / Be quiet on the tee and green / Chin up / Be strong / Be flexible / Save your money / Pay your debts / Be on time / Remember people’s names / Remember the good shots / Don’t dwell on bad shots / Know the rules / Know the lay of the land / Don’t listen to critics / Be confident / Take care of equipment / Leave course better than you found it / Put your own mark on the ball / Draw a straight line on the ball / Get dry shoes / Laugh at yourself / No grumpy golf / Smell the roses / Stay focused / Be loose / Smile / Don’t put a lot of pressure on yourself