Diet: Balanced diet with an appropriate vitamin/mineral supplement. If your horse suffers from some form of foot disease particularly if the condition negatively impacts the hoof wall, consider using a supplement that is specifically developed for this kind of use. Get the advice of your veterinarian and farrier.
Exercise: Regular exercise that is appropriate for that horse will help maintain hoof health as it stimulates circulation in the foot.
Daily hoof care: Clean out and check for any lodged debris, abnormal discharges or odours, or injuries. Look for any signs of excess dryness or flaking for which a hoof dressing might be helpful.
Regular hoof trimming: Talk to your farrier about how frequent this should be done for your horse. Be aware that the intervals may change throughout the year depending on the season and other factors.