Haga's method is great for squares, but you're right, it won't work very well for an A4 (or any rectangle) sheet. You will need to look at the crossing diagonals method for that. Fold one crease diagonally across the A4 sheet, and one line diagonally from one corner to halfway down the edge, and they will intersect at the 1/3 point.
Haga's method is great for squares, but you're right, it won't work very well for an A4 (or any rectangle) sheet. You will need to look at the crossing diagonals method for that. Fold one crease diagonally across the A4 sheet, and one line diagonally from one corner to halfway down the edge, and they will intersect at the 1/3 point.