The fabric kept from an old shirt can carry a memory into something useful.

Keeping and using are not opposites. A shirt that cannot be worn any more can become a cushion cover, a lining or a patch on a coat, and the memory travels into something handled daily rather than into a box that stays shut. That is one way of holding on which does not require preserving everything intact. It also gives the object somewhere to go besides storage.

If there is a garment you can neither part with nor use, consider cutting a piece rather than deciding all or nothing. Keep enough to touch. There is no correct amount and no deadline for any of this.