I did one thing and that was to remove items off our back deck and take off the mat we have before it freezes to the deck. That's what happened last year because I didn't do it in time and had to buy a new one.
Check the antifreeze in the car. Put in storm windows. Stock the pantry to cut down on travel. Making sure the gym equipment is safe and sound are some of the things we do routinely.
Finish getting some ceiling insulation put into place. There's a small patch of ceiling that has nothing except floorboards between the heated indoors and the unheated attic. Thankfully it's on the side of the house we're not using but it is getting colder than usual over there. I want to pull down some more ceiling and the cellulose insulation and get the whole lot replaced with fiberglass.