Fitted sheet folding 101

start here by smoothing out your sheet

  
Lay the fitted sheet on a flat surface, with 2 corner seams at top & bottom
( A B at the top and C D at the bottom )

Turn two bottom corners (C & D) inside out and tuck corner C under A, 
then D under B. Smooth, making a flat rectangle shape

     

Fold the fitted sheet in half from right side meeting in the middle.
Repeat with left side to form a long rectangle.

Fold in half again and once more if needed to suit storage space.

voila !