Take a square sheet of paper, and fold in half
Keep folding until it is a thing cone. Cut small tiangles out of the edges and a zig-zag top
Hang on window or wall to enjoy
My motive in making this craft today was actually to keep birds from crashing into our windows. A bird crashed into this window this morning, and I felt so bad. The bird actually recovered (after being stunned for about half an hour) and flew away, so at least we had a happy ending this time.