Given up? Here’s the solution
1. Taking care only to fold along the dotted lines, begin by folding one end over, making sure you leave a firmly pressed crease.
Then, flip the sheet over and fold the same end the opposite way.
2. Repeat this process at the other end. The aim is to create neat creases that can be folded both ways.
Once this is done, unfold the whole sheet back out flat.
3. Fold the whole sheet in half, lengthways. Then fold the two top corners both ways – in towards you, and then away from you – along the dotted lines. This will create the diagonal creases necessary for constructing the gable ends.
4. Place your index finger right on the outside of the corner, and your thumb just inside the fold. Using the creases you’ve created, pull the top corners down and inwards, to create the gable ends. Using your other hand, press firmly along the new edges.