If it's the Trumpeter P-51, read the article in the recent edition of FSM. It has a workbench Review article.
If it's the Airfix kits, you'll need patience, a gallon of filler putty, more patience, a good stress reliever, even more patience, alot of paint and then a hammer to pound the crap out of it cuz no matter how hard you try, you probably won't be very impressed with the end result. For a more spectacular result, get some C-4 or Semtex and blast the heck out of it. As Big Jim McBob (the late great John Candy) says, "That blowed him up, real good!"