What are some things I can do the night before the event to prepare?

Order takeout so you don't have to worry about making dinner while you're preparing for company. And I'm in agreement with the stiff drink and good night's sleep.

Get a good night's sleep!

To add to what others have suggested about getting out the serving dishes and labeling with a Post-It, I also put the serving utensil that's going to be used in the serving dish. Trivets are assigned to dishes as well. Napkins are usually ironed by the weekend before, but if not they are done the night before (or two, or three). Tablecloth is touched up. Coats from entry closet are taken upstairs to bedrooms to make room. Candles in holders; polish if it hasn't been done. Sterling is usually polished regularly here, but I always go through and check the night before, to touch up; then I rubber band all but what we're not using that night and the next morning, and set it aside. Glasses are checked and put on serving trays. Place cards are made. And of course, I do all of the food prep that makes sense. Most of this is laid out on a master plan within a day or two after scheduling the event, or by the Saturday morning of the weekend before, for Christmas or Thanksgiving. (We always take long hikes on those days, so my advance preparations -- sort of like planning for the invasion of Normandy -- for those meals has become quite routine.) The To-Do list is checked every morning and every evening starting five days before the event. Typically, the night before is pretty calm and enjoyable. As is the day of. ;o) P.S. It seems like an actual checklist / spreadsheet would be a nice item to include in the holiday App!!

As has been mentioned - any food-related chores that make sense to do ahead. Straighten up/clean. Most flowers look best after a day in water, when they open, so trim/arrange those. Lastly, set up bar, pour yourself a good drink and relax. This is supposed to be fun!

I like to prep any food I can the night before, cleaning, chopping slicing and storing in ziplock bags in the fridge until I need them the next day it really cuts my time literally in half having food prepped and ready to go, that includes anything that can be made like cranberry sauce. I also make my pies the night before. I agree with Jessica about having platters and dishes ready and labeled.

Peel potatoes, sweet potatoes, carrots, cut them as needed and store in the fridge with cold water to cover. Set the table, if it's one you won't be using in the meantime. Clean the bathroom. Set fresh candles in holders. Make sure you have batteries for the camera. Snip the stem end off green beans, blanch for 3 minutes, then transfer to ice water, hold in the fridge overnight so they'll cook almost instantly the next day. Set up a cheese & fruit tray, minus the crackers, cover it, and refrigerate overnight.

Set the table--completely--with all utensils and glasses. Get out your serving platters or dishes and label each with a post-it of what will go inside so you can make those decisions in advance and you'll be all set to go when it's time to serve.

If it's a dinner event, I also like to pre-cook the day's breakfast/lunch so I don't have to focus on "extraneous" cooking day-of