Its easy:
1. place sheet on floor
2. Remove cat from sheet
3. try the martha method
4. get mad, remove cat AGAIN
5. pull corners together
6. sit on it till its flat.
7. Shove sheet and flat sheet in the matching pillow case.
8. open closet
9. cram half the stuff back in closet, throw pillowcase ball at the top.
10. Open closet and remove cat
11. shove stuff back in.
12. Try to take a nap since your tired, give up due to cat taking over bed.