You may not believe it, but this hasn't been a huge issue for us. We have yet to organize a "chore chart" or make rules or anything. Everyone is just kind of responsible for their own spaces (bathrooms, bedrooms), and for the common areas we just do what we can when we can. We're all pretty interested in keeping a clean house, and this makes it easier I think.
TOTAL HONESTY: I have on a few occasions been tempted to complain about this aspect of living with other people. There are more dirty dishes, we have to share a washer and dryer, and there is NO END to the amount of mail we receive! But when I think about the whole "speck in your brother's eye, plank in your own" thing...the obvious answer is, "If it bothers you so much, do something about it!" If the kitchen is dirty, clean it. If there's mail everywhere, sort it and put it in people's bedrooms. After all, why would it bother me so much to clean up someone else's mess? Because I'm SELFISH. Because I have an over-developed sense of personal justice and may need to just suck it up a little and try to be a servant. Maybe. I'm just suggesting.
However, like I said, we do not live with slobs. I guess if we felt like we were always cleaning up after one person, it would be different. Not sure what we would do then.