First get yourself a medium to large size gift bag. I prefer to use metallic ones for this ornament, but any bag can be used.
Cut down the side of the bag and around the bottom as shown in the photo.
Make copies of 20 circles with equilateral triangles inscribed in the circle.
Roughly cut out the circles.
Using only a dot of glue in the center of the circle, glue all 20 circles onto the inside of the spread out bag.
Cleanly cut out the circles. Then fold to create the triangles. Once the circles are folded carefully peel away the pattern Do this for all the circles.
Now is the step where you start gluing the circles together. First make a train of 10 circles by gluing the folded edges together. Then make 2 'hats' of 5 circles each.
Make a circle of the train and glue the ends together.
Now take one of the 'hats' and glue each flap onto a flap on one side of the train. Let dry. Then glue the other 'hat' to the other side of the train.
The is the completed Icosahedron. It can be used as a display, gift, or you can run a string through one of the flaps and hang it on your tree. You can make this ornament out of any size circle, but the larger the circle the easier it is to make.