My husband is an expert at folding fitted sheets - he learned the trick from his mom.
It’s still a mystery to me...
I learned watching a Martha Stewart video.
I stuff the fitted sheet into a pillow case. Problem solved.
If you only own one fitted sheet, you’ll never have to fold it.
First, you fold the sheet in half and push the opposite corners into each other. Now the points of the fitted corners are the edges of a rectangle with the elastic edges folded inwards. Smooth out any wrinkles and finish folding the sheet. It will always be thicker than the flat sheet once folded, since the elastic adds bulk.