My outdoor chair cushions were sunfaded and stained but other than that were very usable. I made removable, washable slip covers for them from matching curtain fabric and a sofa throw that had been tucked in a cupboard for years and almost forgotten.
The cushions could almost pass for new again. Luckily for me the fabric had a check pattern so it was easy for me to keep the seams reasonably straight. Cost: FREE :)