Proper care and maintenance of your doors begins with proper installation to ensure the door swings smoothly, latches easily, and closes tightly. For exterior doors, you should also ensure an appropriate overhang to help protect it from the elements.
With the door properly installed, you should regularly inspect and maintain the weatherstrip to avoid any long-term damage to the door. This will also help determine if there has been water leakage, or potential energy loss. Look for gaps, torn, cracked, or brittle weatherstipping. The door sweep should also be visually inspected in a similar manner. Close the door and check for gaps between the sweep and the sill. Many sills are easily adjusted up or down to close any gaps.
Inspect the door finish for any signs of cracks, fading, flaking or any other damage. If any of these signs are found, it may be time to have your door resurfaced and/or refinished to prevent any additional damage and extend the life of your door.