And this is probably obvious but when you are focusing on everything else around the tournament, sometimes you forget about the weather. Be prepared for almost anything. Since you have a caddy, stuff your bag full of gear, even if you doubt you’d need it.
I played a tourney once where the forecast for the next day was sun and no clouds.
Woke up, still forecasting sun and no clouds.
Get to the course, sun and no clouds.
First tee, clouds start rolling in.
2nd and 3rd holes, torrential rain.
Rest of round, sun and no clouds.
Had no rain gear with me at all. Not even a backup glove so I stuffed my glove deep in my bag during the downpour and played barehanded. Played those 2 holes in +7, rest of round was +1. Those two holes made a 20 place difference.