 There's one more really important thing to do between the time you get pre-approved for the mortgage and the time you actually move into your new home. And that is stop spending money. Really. Please don't buy a new car or get a house full of furniture. Don't buy a new grill, a new lawnmower, and a new washer and dryer. Because if you do all that using credit, you could completely derail the mortgage you already have.