The mailbox of the house we moved into had hummingbirds painted all over it. I wasn’t really interested in buying a new mailbox either, so I primed it, spray painted it black, designed a layout for it, and got my bosses wife to cut some vinyl decals for me.
Extremely easy and cheap (free!) Most sign shops will do cut vinyl for relatively cheap. They can usually help with your design if you aren’t familiar with vector graphics or Illustrator (my preferred vector program) I blurred out our address… (I’m a pretty private person) but you can still get the concept.