Simple built-in to create a mudroom and/or storage anywhere from an entry, to kids room or in a laundry room by adding shelves or a deeper bench for sitting. Put drawers under bench or have the seat lift up to store things.
Love the backing of the bookshelf would paint the actual bookcase a different color! DIY Country Decor: Pallet Bookcase Tutorial Maybe a way to sturdy up the cheap book shelves from Target and Walmart or Ikea.
add wood wallpaper to the kick plates of the stairs. Those rolls are expensive but you would only need one. Not practical with white treads though, it will be stuffed up from black shoe soles in no time.