Working one room at a time was exactly how I did our house. And it was a series of steps that involved lots of sorting. First was going through and deciding what could be thrown away completely, while at the same time making "piles" of like things together. The second time around was deciding what was to keep and what was to be put into the rummage sale, passed on to someone, or taken to GW. The final sort was deciding what to do with what we wanted to keep and making a certain decision about whether we really wanted it or not. All the while, we cleaned, wiping window seals, baseboards, sweeping, mopping, rearranging furniture, dusting. My DDs had to sleep together several nights when we worked in each of their rooms, but it was worth it to them when it was all finished.