There are 18 Origami Designs in Origami Christmas Tree Decorations:

Design	Designer	Page	Details	Photo
Show only designs with photos
Decoration Geometric and other shapes	Alice Gray	6	Square 2 units
Decoration Geometric and other shapes	Molly Kahn	6	Square 2 units
Decoration Geometric and other shapes	Robert Neale	7	Square 2 units
Decoration Geometric and other shapes	Various	7	Square 2 units
Decoration Geometric and other shapes	Alice Gray	8	Square 2 units
Decoration Geometric and other shapes	Molly Kahn	9	Square 2 units
Decoration Geometric and other shapes	Ted Norminton	10	Square
Decoration Geometric and other shapes	Molly Kahn	11	Square 2 units
Decoration Geometric and other shapes	Rae Cooker	11	Square
Decoration Geometric and other shapes	Takekawa Seiryo	12	Square 6 units
Decoration Geometric and other shapes	Betsy Kitch	13	Square
Module Geometric and other shapes	Mitsunobu Sonobe	14	Square 6 units Also in 12 Months with the Unit Origami Also in Doctor's Origami Dream Book by Toshikazu Kawasaki Also in The Encyclopedia of Origami Techniques by Nick Robinson Also in Papiroflexia Basica by Vicente Palacios Also in ORU Magazine 13 Also in Origami - 30 fold-by-fold projects by Paulo Mulatinho and in other sources...	Folded by Meenakshi Mukerji
Decoration Geometric and other shapes	Jack J. Skillman	16	Square 2 units Also in Origami 2 by Robert Harbin Also in The Flapping Bird by Samuel L. Randlett Also in The Magic of Origami by Alice Gray and Kunihiko Kasahara	Folded by Marco Abate
Decoration Geometric and other shapes	Molly Kahn	17	Square 3 units Also in Origami El Mundo Nuevo by Kunihiko Kasahara Also in NOA Magazine 489 Also in Origami - Easy-to-Make Paper Creations by Gay Merrill Gross Also in World's Best Origami by Nick Robinson Also in The Magic of Origami by Alice Gray and Kunihiko Kasahara Also in The Origamian - Vol.07 4 and in other sources...	Folded by Nick Robinson
Decoration Geometric and other shapes	Traditional	18	Square
Decoration Geometric and other shapes	Wayne Brown	19	Square 2 units
Decoration Geometric and other shapes	Unknown	20	Square 8 units
Decoration Geometric and other shapes	Lewis Simon	21	Triangle 2 units Also in NOA Kessakusen 2 Also in NOA Magazine 3 Also in Origami Deutschland 2005 Also in Pajarita Magazine 9 Also in WCOG Newsletter Vol 3 No 3 Also in Origami 3 by Robert Harbin and in other sources...	Folded by Marco Abate