Put anything that belongs upstairs on the bottom stair,anything that belongs downstairs on the top stair.Then everytime anyone goes up or down,they bring their belongings with them.
Keep a tube of denture tablets (steradent?) for soaking badly burnt pots,completely lifts it.
Clean bathroom mirrors with washing up liquid,they don't get dirty so quickly the next time.
Buff windows/glass with a sheet of scrunched up newspaper,completely removes smears.
Use a slice of white bread to 'mop' up pieces of broken glass.
If you can't be arsed to clean much,make cleaning your kitchen sink your absolute minimum.A shiny clean sink makes the whole kitchen look cleaner (whereas a dirty one makes the place look filthy)
Smear some fabric conditioner,or place a tumble drier sheet,behind a radiator.It makes the place smell like clean laundry.