First is going to have to be;
1 Pick up after yourself
2 Put things back where you got them from
3 Picking a pile of gaming magazines up and putting them down somewhere else on the floor but in a more tidy pile is NOT tidying up!
4 Pick up after DS while getting him to help you
5 When clutter gets to maximum density, make a joint effot with the other adult to clear it, not argue that "you do it all the time" when all you actually do is point 3 overe and over again