Location, location, location!
1 Prepare dishes ahead of time.
2) Freeze those you can. This helps the efficiencuy of your cooler.
Favorites of mine are:
1) Put a tarp under the tent, making sure no part of the tarp is exposed. Fold the tarp UNDER itself so the size matches the size of the tent.
2) Ensure your rainfly is installed properly. Use a tarp and clamps if the rainfly is missing.
Use a shammy cloth to bail out the tent. Wipe up any puddles. Wipe down any moisture. Take anything out that got wet. Hope for sunshine to help with the drying.
A propane heater will keep you warm. I like the Mr Buddy heater, It uses the small green propane tanks, and works great in a tent.
Bring some foot powder, and use it often. It'll keep your feet dry.
Those magic cool-off towels do work. Just dunk it in water, snap it, and place it on your neck, forehead, face, and ears.
Even better, get a fan. I like the type that use the 18v batteries I already have for my tools. Ryobi and Dewitt both offer choices in sizes. I prefer the smaller one because it is more portable (and still does the job),
Bring extra battery packs to charge your phone. I've added solar panels to recharge the battery packs.
Dollar General has $1 pool noodles - use them on your tie-lines to help keep trippy hippies from walking into your lines. Use them under the corners of your canopy to help avoid pooling rain water.
You can use a pop-top to repair that flip-flop. Just break off the tab, and use it to repair the break.
Expect worse weather than the forecast calls for. Hope for better, but be prepared. Always bring more socks than you need. Always bring more water than you need. I bring extra chairs, extra battery power, and an extra sleeping mat. Bring everything (that fits) that makes you comfortable.