Put a half-cup of bleach into the fresh water tank before filling for storage. Run each faucet until you smell bleach.
Drain and refill with fresh water before a trip. Don't forget to flush faucets.
Keep a little water on top of toilet knife-valve. (For storage add a Tbsp. of veg oil first.)
Inspect tires and Check tire pressure before every trip. (Store with tires on wood or old carpet, not on dirt or concrete. Some folks remove wheels/tires for long storage.)
Wash it after every trip.
Check battery water every month. (Change battery a year before warranty expiration.)

Leave it plugged into shore power when stored.(I leave refer on continuously as it's stored at my home. Defrost it when inside fins are heavily iced.)
Using compressed air, blow out the water-heater flue and refer heater-chimney/flue annually.
Lubricate hinges and wipe door/window seals down with Silicone lubricant sprayed onto a rag annually. (NEVER use anything containing ammonia on plastic windows, including Windex with ammonia.)
Inspect brakes and repack wheel bearings approx. every 20K miles or 5 years. (This will contradict what "shops" will tell you, which is to repack bearings every year. They will charge you for that. Wheel bearings in a trailer are no different than your Dad's car. How often did Dad do his car?)
Save $1500 and frustration with dealers sloppy work and careless damage.
OR>
Take it to your Airstream dealer anally. (pun intended)
If you use a Scotch-Brite pad and clean up your boarding-handle, then paint it with automotive "clear coat" (sold wherever auto touch-up paint is sold) you will be proud of yourself. It will last years afterward.