I do my bike-fixing outside if the weather's good. As far as cleaning the frame, I just don't do it. Having dirt on the paint will not cause the frame to break any quicker and the cleanliness on a bike ridden every day won't last anyway.

I adjust brakes, shifting, etc. without a workstand- I just lean the bike up on something and fix what needs fixing. It's not the most convenient thing but I only have to do it every few weeks anyway.

During the winter I try to do my maintenance at times when the bike does not have any snow or ice stuck to it. I bring the bike inside and usually lay it on its side in the living room where it will be hard to walk by until I'm done fixing the bike. (extra motivation to get stuff done quickly, since my sweetie doesn't like to step over me and my bike stuff). We have hardwood floors, but I have in the past used newspapers to catch dirt that falls off the bike if the bike was particularly dirty.