Fold your paper into a square, then fold into a triangle. Fold some more. A bit like this:
Here’s the template for mine. I found it on the internet, drew it on and then carefully cut it out. Please bear in mind that I’m not naturally creative, crafty or artistic so if I can do this, anyone can!
You can probably find and make a more intricate, delicate design. If you have a craft knife, there’s probably a lot more you can do, as scissors can be hard work! Anyway, this is the finished product: