Nice to hear all the catch-as-catch-can space users.
I sew in the basement, although it's an above-ground bright area. In fact, my "complaint" is that I have no wall space because of all the windows! Almost all our guests walk in through this area, and it's all open so there are no walls to define a certain space as my sewing area so I have to consciously keep it from travelling around the house. The only real drawback is having to completely rearrange if we have company because it's also the area where we set up the spare bed.
Like others, I let the clutter happen during a project and always clean up to start the next one with a fresh, clean area.