I love my basement sewing room. My basement is unfinished, we don't have a huge problem with water so I haven't had any problems. The basement stays the same temperature all year round about 60 or 65. Just wear shoes. I have a huge braided rug on the floor and my sewing cabinets are on that. I also have a Treadclimber that is mostly used for a quilt rack instead of it's intended purpose, but that's another story.
I dragged a cable through so I could hook up a TV to watch cable.