Don't be afraid to load your tree with lots of colorful ornaments. At Christmas many collectors like to deck their tree with classic ornaments. However, collectors realize that antique ornaments from the 19th to the early 20th century are getting harder to find making their price tags quite expensive. Since the price is high and they are becoming rare, many collectors are turning to ornaments made in the 20 years following World War II which would include the '50s and '60s. They are especially interested in those made in America.
Bookstores have plenty of good books on the subject of collecting.
You can also obtain a subscription to different magazines on collecting. Two good books on this subject are Christmas Ornaments, Lights and Decorations, by George Johnson, and Holiday Collectibles by Lissa Bryan Smith and Richard Smith. Also, you can search online for information on Christmas ornaments. The idea of decorating a Christmas tree did not become official until the early 19th century. When people first started putting up a Christmas tree they didn't trim them with the type of ornaments we use today.