first get a pice of lined paper, and fold and cut it like in the picture so that when you unfold it, its sqaure.
Step 2: Step 2
now, fold so there are creases like the picture.
Step 3: Step 9[no i lied, its 3]
now, push like in the picture so it looks like rocket fins, then staple at the bottom so they stay together. if you want, you can stick a pencil through the middle and actaully kill someone, but i wouldnt reckomend it.