My challenge was to make my brand new classroom feel like it belonged in a gothic style castle.
Students who choose to buy an owl, keep them in our school owlery. Every student has their own mailbox. The Owl Post workers are in charge of sorting the mail from the outgoing box.
The giant pendulum is from the Hogwarts Clock Tower. I also posted the Hogwarts school song, my version of the Sorting Hat song, and a description of traits and information for the three houses.
I made sure to include envelopes and stamps at the Owl Post for the students to use. I also included a few extra details like two of Harry's Hogwarts acceptance letters and a Kwikspell Correspondence course letter addressed to Filch. If you open the envelopes the letters are all there. I love to leave little details for my students to eventually discover.