I haven't read the entire thread, so forgive me if any of this is 205
I have a thermarest pad I lay on the garage floor whenever I need to lay down next to the bike to change the oil, check the tires, whatever. Way better than lying on concrete.
My bike is supposed to be upright when the oil is checked, but doesn't have a centerstand. I got a small mirror with a telescoping handle, so I can check the oil while sitting on the bike. I got it from Sears.
Before I work on the bike, I always sweep the garage floor. That makes it a lot easier to find that washer I always drop.