Identify people, events, and dates. Use black and white photos because the process is more stable and will outlive color photos by many years. Color photos will fade.
Store photos away from light and placed in plastic or paper protective covers.
Light may cause fading and brittleness. Gritty dirt and dust will be abrasive to photo surfaces. Store negatives separate from prints when possible. Place photos in a commercial archival-quality album. Skin oil will damage any part of the emulsion that you touch.