I bought some fairy and tree paper at the local Scraps of Love paper store.
I made a tree pattern and cut it out. I bought plywood fairy door parts on Amazon and painted them. They came in 4 parts so it was easy to paint.
The only down side is that it costs a lot to mail the card. The Post Office treats it (and prices it) like a small package. So far they haven't accepted fairy dust as payment either.
Are you a card maker or a DIY'er? If you'd like free instructions and a list of where to buy the components I used, sign up to follow me.