My wife and I deep cleaned the house then made a visual task board with different small (less than 30m) chores assigned to one or the other, on rotation, on a weekly basis. The house has never been less than acceptably clean (to a mother-in-law standard) since :)

Also, decluttering and reorganizing all storage spaces using the Marie Kondo method (where it made sense) helped a lot and once done it's hard to relapse.