String popped corn for garlands, paper chain garlands, little balls of aluminun foil can be strung into a garland,
Origami stars and animals can be ornaments, small toys, popcorn balls, candy canes, and cookies can all be hung on a tree or wreath,
A red or green tablecloth, blanket or sheet can be wound around the bottom of the tree as a tree skirt.
One of the lovliest table settings I have seen was at a friends house she put tea light candles in tea cups and placed them on thier saucers with Gingerbread men as place card holders.
I have written a hub on this subject called Our Christmas Decor Through the Years and another two on gifts one called 10 Easy to Make Christmas Gifts that Don't Cost an Arm and a Leg and the other named Buy Small Gifts All Year that may help to give you some ideas.