Most bedrooms that feel off are not badly decorated. They are badly measured: a rug 2 feet too small, a nightstand 6 inches too low, one ceiling light doing the work of four fixtures.
Your cabinets already decided the height of your backsplash. What is left to choose is material, termination and how the range wall gets handled, and that is where most kitchens go sideways.
The decisions that determine whether a bathroom remodel is good get made in the first week, before a single tile is chosen, and most of them are dimensions.
Moving a toilet 18 inches can cost more than every tile in the room. Knowing which changes are cheap and which are structural is what separates a good bathroom from an expensive one.
Most desks are not messy because of the person using them. They are messy because there is nowhere within arm's reach for the six things that get used every hour.
The tile you pick matters less than three decisions almost nobody makes on purpose: how high it runs, how wide the grout joint is, and how the last edge is finished.
Count your shoes and measure your tallest boot before you buy a single shelf. Those two numbers determine the whole layout, and skipping them is why most closet shoe storage runs out of room in a year.