Really Pottery Barn?! I love your stuff but $79 for a moss letter!
There are all different letter styles you can use. Just find one on the computer you like and trace it out on some wood or go to Hobby Lobby like I did and get one for two something and cover it. I think the key to this is using sheet moss because it give it a cleaner more even look.
This is what I started with. I am doing this for indoors so the cardboard letter is fine. I used the sheet moss and I traced the letter on back to see how how I would need to cut.
I thought it would be sticky but it wasn't. That's what hot glue is for. I actually rolled the letter half way to wrap around initial. I glue and cut to fit. I only used half of a sheet. Making this project cost around $5.50. Pottery Barn eat your heart out!
I tied it to a frame and hung it on the inside of the door to my sun room. You can add anything to it like Easter eggs a nest or change it up for the holidays. I think I will do one for outside now!