The best way to make sure cashmere garments last is to handle them carefully. Cashmere should be cared for like any other fine woolen. To keep them looking new, follow these steps:
Hand wash knits with cold water, using a fine washable soap. Woven garments should be dry cleaned.
Fold knitwear with tissue and store flat in a drawer; do not hang on hangers.
Hang woven garments on padded hangers, zippered and buttoned with pants and shirts on hangers designed for them.
Give garments a rest between wearings for at least 24 hours; wrinkles will vanish.
Treat stains as quickly as possible; rinse immediately with cold water; hot water may set the stain. If garments get wet, allow to dry away from direct heat, then brush with the nap.
At season's end, clean and store garments in an uncrowded garment bag in a cool, dry place; fold knits and store in a chest or drawer; moth crystals or spray will help protect garments from moths.
Source: Cashmere and Camel Hair Institute