Lay the sheet in front of you inside out.
Place a hand in each of the two corners on the shorter side of the fitted sheet and bring them together, one hand covering the other so one corner wraps around the other.
Pick up the far corner of the sheet hanging in front of you and tuck the new corner into the hood of the two folded corners.
Pick up the fourth corner and tuck it into the other three corners.
Lay the sheet on a flat surface in front of you and smooth out the wrinkles. It should look like a folded sheet with the fitted corners all tucked together like a hood.
Fold the sheet from the outsides inward to hide the elastic fittings.
Continue to fold into a rectangle of the desired size.