A woven Hexagonal Bipyramid would do very well for a Christmas ornament. Just add a piece of string on top. From the same pattern you may also make a bipyramid with 4 or 8 faces.
For the Hexagonal Bipyramid you need to cut out 2 times 3 pieces. You may use 2 or 6 colours as you like. After cutting out, score and crease along the dotted lines. All 6 pieces should be creased in the same way. Now you weave together two pieces of different colour. The flaps must all be located at the same pyramid (the lower). To keep the two pieces fixed you have to do quite a lot of gluing. Actually you need to fix most of the rhombs with glue. Next you weave in the other pieces one by one – and fix with glue. Then you close the upper pyramid by weaving together the first and the sixth piece – and fix with glue. Finally you close the lower pyramid by gluing the triangles together using the six flaps.
The form may also be woven from two pieces only. I include an alternative template.
Starting is, however, a little more difficult as the long arms tend to be much entangled. First crease the two pieces along all the dotted lines so that they swirl in opposite directions. Cut away the two small triangles. Start weaving together the two pieces near the flaps. One flap should be located in the upper pyramid and one in the lower. Just weave together the faces as they present themselves and remember to line up and fix with glue as you go along. Having woven all 12 faces you meet the flaps again. Use those to close the form and fix with glue.