Step 1: Printing
First of all download the template which can be found right here, below in the pictures.
Then print out the template and start cutting.
Step 2: Cutting
Cut along all 4 sides as exact as possible. If you can use a cutting machine otherwise just you scissors.
Step 3: Folding
Now fold all of the triangles one on top of the other so that you end up with a triangular spring. Do this both ways to make it very flexible later.
Then make a horizontal strip out of the triangles as visible in the second picture.
Step 4: More Folding
Now with the strip fold it into a hexagon leaving the triangle with the x on it upright for gluing.
Then glue the triangle onto the hexagon and you are done.
Step 5: Coloring
This step is optional but it is easier to make a fineman diagram with colors. If you do not have that many colors you can just change in shape or symbol. If you want to you can also draw sick patterns on to them to make them look a lot cooler.