Fold an A4 like this.
Cut the excess part.
We're going to use the extra part.
Fold a corner like this. DON'T CREASE IT. Just PINCH the end of the fold. Unfold.
Fold the top part to the pinch that you just made. Unfold.
Fold it in half. Lengthwise. Unfold.
Fold the other corner to the center fold. Like so.
Fold the edges to the middle.
Fold the edges AGAIN to the middle but ONLY until the part you folded at the top (I know it sounds confusing but focus on the picture to understand what I'm talking about).
Fold the top part backwards.
Fold the corners like this.
ιи му σωи ωσяl∂. нαнα.