I have a 12x 13 bedroom just for sewing. I have a Grace frame with a Juki machine, my sewing machine, shelves for material, and DH took the closet doors off from one of the closets and made me a recessed work table with a cabinet underneath that has six drawers in it. Amazing what you can get in a small space and still not feel crowded.
Best thing about my sewing room - One of our bathrooms connects to it!!!!!! Give me a small frig and a microwave and no one would see anything of me for weeks at a time!!!!