I worked as a short order cook for a spell, a job that doesn't even pay the bills much less leave extra in your pocket, the times when folks stopped and brought me a tip for a good meal. ##### that made my week, not just my day.
I figure even if the shower is not perfect, as long as they didn't forget to flush or dry the floor I leave a dollar. April leaves a dollar if she didn't have to wait more than ten minutes. Set your standard if the cleaner lived up to it tip! I have left as much as five, when for no reason the cleaner gave us two extra towels each and asked if we needed anything else. I don't tip if I have to wait forty minutes because the cleaner just won't work. You can tell just walk back there and see how many doors say vacant. We were at a TA in CA once there was a water pressure problem, we counted ten signs saying "We have a water pressure problem, Sorry for the inconvenience." It was halfway between LA and Phoenix you know the place 'middle of nowhere', anyway there must have been ten drivers stop and yell at the cleaner; because of the bad water pressure. Like they didn't know, and had to wait nearly an hour for their turn. We both tipped that night. Its a thankless job, would any of us be willing to do it for that pay? Besides if you keep track of the amount all tips are deductible. It's a win win.