I didn't get to plan my sewing room as we bought a house that had a 30x30 attached garage with an apartment above it and that become my sewing studio.
1. I love having a bathroom with a washer/dryer hookup. We modified what was there to use a full size front load washer with a full size dryer on top. No hauling fabric to the laundry room in the basement for me! I actually do most of my laundry up there so I can monitor it while sewing (have dress cloths that need to be removed promptly. And when I'm too busy finishing up something to deal with the "call of nature", I don't have far to run when nature becomes insistent!
2. Love the walk in closet - it's narrow with shelves on both sides, and it's perfect for my stash. We put track lighting so I'd have lot of light. I put clear totes for the top shelves so I can see what is in them. I have a stool to easily get them down.
3. The bedroom is perfect for my LA. I love being able to shut the door and not worry about the cats using a quilt as a hammock. the separate room also allows me to keep the shades pulled without keeping it dark in my sewing room.
What I don't like
It has track lighting in the main area all on one switch, would love to be able to only turn on half at a time. I have desk lamps at each machine to give lots of light where I'm working.
we did pull out the carpet and install luxury vinyl.