Step 1: With the sheet entirely inside out, place your left hand into any corner, and your right hand into the next closest corner.
Step 2: Placing your fingers into the seam corners match up the adjacent corners and place one corner into the other so the sheet is now folded in half.
Step 3: You now have two corners in each hand. Bring your hands together and flip the corners from your right hand onto your left hand, making sure all the seam corners are touching.
Step 4: Grab the right edge, and gently shake the sheet, allowing the elastic edges to fall toward you. Lay the sheet onto a flat surface. (Note: make sure the left and bottom edges are straight and square.)
Step 5: Fold in thirds length wise and then in thirds again
Step 6: Smooth out, and be proud of your awesome work!
Step 7: I always fold my flat sheet with the wide edge showing so I can tell them apart.