since it's december winter themes are alwasy good to go with... winter wonderland, candy land with lots of candy canes, santa's workshop. however, sometimes it's fun to get more creative and do something opposite... at the beach in the winter, summer fun. music is always a good choice. we did one that was for the 70s and played lots of disco music, had strobe lights and lava lamps... etc. ppl still have those so you can borrow them. one of my favorite places to shop is Link Removed. they have great decorations and they are pretty inexpensive. also remember to take care of the decorations you buy/make and you can re-use them year to year!