If you decide to break new ground and you don't already have a mailing list then be sure to check into EDDM (every door direct mail). The only differnences between that and saturation mailing is that you need to mail a more specific sized piece and you dont need a mailing list as you will go online (USPS) and pick specific routes. I am doing this so that I can target the exact neighborhoods that I want to try to get into. Its about 14 cents per piece I believe. Good Luck
IMO if a design did well keep it if not scrap it. I wouldnt use it more than 2 yrs for the same houses just figuring if you had a chance to get them and didnt then that design didnt do it for them.