Use one square sheet of paper
Fold the paper in half horizontally
Unfold it
Fold the top and bottom edges to the center crease
Unfold it
Fold the paper in half vertically
Unfold it
Fold the left and right edges to the center crease
Unfold it
Cut or tear the paper into two equal rectangles along the vertical crease
Take one rectangle
Fold one corner diagonally to make a triangle
Fold the opposite corner diagonally in the same way
Fold the paper in half along the center line
Fold one end corner inward to form a small triangle flap
Fold the other end corner inward in the opposite direction
Repeat with the second rectangle
Place the two folded pieces together at right angles
Tuck each flap into the other piece to lock them together
Adjust the points so the star shape is even and flat