Although I'm really loving the numbers above, I wanted to make something cheap and easy, so I headed to Hobby Lobby to see what I could figure out. After perusing the aisles twice, I finally decided on some wooden numbers at $1.99 a piece.
I already had some flat silver spray paint on hand. I first spray painted the letter white to make sure that I didn't want that color on our front door. I didn't - too bright. I then painted over them with the flat silver.
I didn't want to use anything permanent to attach them to the door because I don't like anything too permanent, so I ended up with this: