Lucky girl! The best thing you can do (and I do this even when I want to rearrange furniture in any room) is to draw your floor plan on gridded paper, to scale. Show where the windows, doors, outlets, overhead lights are. Then draw on gridded paper, to scale, all the furniture you plan to put in the sewing room. Everything you have, and want to have, including your design wall, bulletin board, ironing board, as well as the cat's basket (which you may or not have
Cut out the pieces.
Arrange the furniture on the gridded room layout. Rearrange them. You'll see the best lighting (and shadowed) areas, where to put furniture in relation to each other, etc. When you move your stuff into the room, you'll probably change some things around. But doing this method will hopefully keep you from having to change the big things.
Windows are lovely, but you don't want to be looking into the sun while trying to work.
I would draw in a large walk-in closet, lined with wire shelves, to store fabrics, batting, UFOs, etc., so they wouldn't be in the sun, and out where it would look messy.
I currently have two ruler holders on the wall behind my cutting table. I have wire shelves over the cutting table where I can put odds and ends that I need every day, such as odd rulers, wireless speakers, pencil holder, a turning thingie (made to be used in the kitchen for cooking utensils) where I keep my rotary cutters, measuring tape, protractor, q-tips, etc. I have a tiny drawer unit in which I keep large and small safety pins, paper clips, rubber bands).
I have bookshelves for books (!), quilting videos and my tiny TV, one contains baskets that contain tops to be quilted, semi-finished projects, magazines, and those little pretty decorating objects you simply have to display.
Since I can't fit any shelves or drawers under my folding cutting table, I just have baskets and a cute laundry hamper in which I store rolled fusible, freezer paper, interfacing. The large square-up rulers are under there, also.
Along one wall is a small desk that has my computer and printer, that I can reach by just turning my chair from my sewing table, which is in the middle of the room.
Hope all this helps! Brita