Dirty Clothes - Keep these in the garage, utility room or laundry area. This especially applies to diapers.
Garbage - Take all trash and garbage out of the house. Make sure no produce has gone bad in the pantry and that nothing is in the disposal. Put a citrus fruit rind in the disposal to give it a nice clean scent.
Pets - Clean up after the dog and move the cats litter box into the garage or out of the house. Make sure there is not any pet hair or dust bunnies on the floors.