The wreath is made from ten linked truncated octahedrons. Each truncated octahedron is made from 24 one-piece triangle modules. Diagrams for folding the one-piece triangle module may be purchased separately as a one-page e-book or can be found in the e-book
"How to stretch a dodecahedron and how to stretch an icosahedron." They can also be found in "3D Geometrical Origami" or "Multimodular Origami Polyhedra", both published by Dover.
The modules are folded from equilateral triangles. Instructions for making equilateral triangles can be found in the two Dover books mentioned.