Hi Kim, here is a video to help you build one. It looks fairly simple.
You're very welcome and good luck with the cornice.
Here's a video that might help you - https://www.youtube.com/watch?v=qWZgJJh9lZI
Kim,. Google this and it should give you pictures, if you search. You can also borrow a book or books from the library, on this subject. Ask the reference desk person to help you find the books you need. No card, show your driver's license to borrow books.
Thank you Chas for all the information!