I just finished a quilt today and cleaned the studio to get ready for the next project. I always put the tools away when I finish a project, but may have them out near the machine during the work. The project I am working on now is curtaiins for the kitchen. I used my rotary cutter, ruler, and mat to cut the fabric, so I have those handy for now. Once the fabric is cut (a few more pieces tomorrow), I'll put the cutter and rulers away for a while.
In other words, I have things out and handy during work sessions, but always put them away at the end - maybe on a fabric scrap near the machine if I'll need them the next day, or in the drawer where they have a permanent place between projects. I try to always leave fabric folded neatly, too. I'd rather have things tidy and ready to use immediately when I walk into the room to work.
Now, don't ask me about the floor - I don't worry so much about it until I sweep or vacuum at the end of a project. I guess that's my next "area for improvement", eh?