Peppy music, bright lights, putting the largest things away first --- working only on one side of the room.
Decisions: keep, not sure, and release.
When you want to "release" something from your collection, put it in a designated box. Handle it once, then move the box to the car for donation delivery, designated spot for trading with friends, etc. You will - I promise - get in the habit of putting the release items away as you see and/or touch them!
Dream big, but don't feel sorry for yourself. Think of why you want something for your sewing room. You just might have a bright idea and discover a new use for something you already own. (I just released some tablecloths and moved the table runners to the linen closet. That freed up the large bottom space in a chest of drawers. Now, I have all of the computer accessory cords, SD cards, CD blanks, DVD blanks, and camera equipment in one easily accessible spot. I'm so proud of myself that I almost broke my arm patting myself on the back.)
Good luck
