Well it might be a little more difficult right now because the snowflakes aren't around yet, let alone the ornaments. Do you have any festive stuff saved from last year? I made sure to save some stuff and I've put it out - I have the illuminated tree, present, deer, and snowflakes out by my house, and the large festive tree right next to my house. Then I have the festive sleigh and pile of gifts out in front of Resident Services, along with a smaller festive tree, and the celebration candles on a barrel next to that. Holly bushes might help things out a bit too, and it doesn't hurt to try to create a more festive palette with your flowers. I have green mums, red windflowers, and white roses around Nook's, and red and white roses by Able's. There's also a regular sleigh DIY that you can craft some of, and put out by your villagers' houses if you'd like.
It was really hard for me to get into doing the things that I did, because it still looks like fall right now. But I knew that if I waited, then I would only have like two weeks to enjoy festive stuff before Toy Day is here. Even less if we wait for the ornaments on trees as those don't start until the 15th I believe.
If you need festive stuff, I would definitely hit up the other forums and see if anybody is willing to help you out with that. Or if you don't mind, you can always time travel to get stuff too, but I know that I don't like time traveling forward at all, so that may not be an option for you.