This is a very nice Christmas ornament that I tried to make with plastic from a plastic bag, but you can also make it with paper (from books or newspapers, for example) or whatever you want! :)
It's very easy to make and the result is really, really nice!

PS: this is my first "step-by-step" and as you can probably notice, English is not my first language, so I hope this is clear enough. If there is anything you want to tell me please leave me a comment, I appreciate knowing what you think very much!

Step 1:

Take your piece of plastic (or paper) and divide it in at least 12 sections and cut them. I made them 22cm long (about 8.66 inches) and 2cm wide (about 0.79 inches).

Step 2:

Take one of them and fold it in half then glue it.
Do the same for all 12 strips.

Step 3:

Now take 3 strips and weave them with other 3 strips as you can see in the picture.
Glue them together to keep them still.
At first they will often move so you just need a little patience :)

Step 4:

Take the two perpendicular strips at the corner and glue the tips together.
Do the same for all four sides.

Ok, the first side of the star is done!
Now take the 6 strips left and do the same thing you have just done to create another "half star".

Step 5:

All you have to do now is taking the two sides you have and put them together, one against the other. They must have the same sides facing. Rotate the one at the top to make them fit perfectly.

Insert the remaining strips in the other "half star" and glue the tips with the ones you glued together previously.

All this is harder to explain than to do so please take a look at the pictures, I hope it's easier to understand this way!

And voilà, the star is finished!