Storing your artwork is mostly common sense. Make sure the frame is securely covered with foam or soft padding to ensure that it cannot be chipped or damaged in whilst in storage. Cover the image with a sturdy board, or loose bubble wrap at minimum so that the artwork isn’t exposed to dust and debris.
Avoid bubble wrap pressing against the front of the work as this can cause damage itself. Keep the artwork in a relatively cool (room temperature) and dry place; water is a major threat to the preservation of art and so be sure not to leave it resting against an area of damp or in a non-watertight loft.