1. Place your hand into the pocket of the sheet with the underside of the seam facing out.
2. Bring the next corner on the short side of the sheet, the width of it, to the inside out pocket on your hand so that they are one over the other with the underside seams together. You should be looking at the good side of the sheet.
3. Repeat with the remaining corners so that all four corners are folded into one. Place on a flat surface and smooth until the edges sit as flat as possible. Don't worry if you find yourself pulling the elastic quite far into the the middle of the sheet. Smooth flat.
5. Fold the opposite side into the middle so that the two edges meet in the centre of the sheet. Smooth flat.
6. Fold in half lengthwise. Smooth flat.
8. Fold the bottom third over the rest of the folded sheet. Smooth flat.
That's it!