When not in use empty the pockets of the garment and hang on a solid shaped and curved hanger. This helps prevent distortion in the shape of the garment.
When storing your clothes keep them out of the light (both sunlight and artificial light). UV light damages dyes in clothes.
Rotating your wardrobe between seasons has the advantage of stopping your clothes from getting squashed and creased. Clothes like to breath!
The main cause of wear in clothes is dirt, dust and grit that accumulates in the fabric. Regular brushing does much to prolong the life of the garment.