I made this the other day.......
I have seen similar (sorta) ones at Pottery Barn for $79. See below
I made mine for $12 and I am going to tell you how.
I used the following materials.....this is for all of you visual gals like myself :)
Foam Board. I found mine at Hobby Lobby (Heaven on Earth) for I think $5. I got the 1/2 inch size
After I drew my letter on the foam board I cut it out using my handy dandy exacto knife. I think I regular knife would work though. The foam board was pretty easy to cut and work with.
I bought some green spray paint so the white foam board wouldn't show through at all. I just took my letter "C" outside and gave it a quick spray. It only took maybe 30 minutes to dry.
I found my Spanish Moss at Walmart. I used almost a bag and a half. It was $2 per bag.
Then I used my glue gun to glue the moss in place. There is really no method for this. I just pulled a handful out, squeeze some glue on my letter, and mashed it into place. I burned my hand several times....OUCH! Oh, that moss is VERY VERY messy!! Don't even try to clean up until you have the wreath outside!
After you have all of the moss on and all of the little holes filled, hold up the wreath and trim off the excess with scissors. You will basically trim and clean it up like a shrub. Hang it with a ribbon of your choice and that is it.
P.S. If you make one I want to see it :)