The fist two response just about sumed it up carpet and shelving. I like to make my shelves out of 3/4" X 5" wide plywood. place at or slightly below the windows. I also put indor/outdoor carpet on it. I also like a shelve on the right hand side (since I'm right handed( at about 18-20" for STUFF.
If you carpet the walls and floor that will cut down on alot of noise. I make
my blinds 5X5 and use "R" panel or some outher type of metal for two reason, I don't like to paint, and it last. I built my blinds "to last" because I got tired of keeping them in repair every year.
Let me just say this if you are not in a hurry let imagination go wild. You may have those that laugh but hey it's all about having fun RIGHT?