A dish washer is just that, it"s not a garbage disposal.... scrape off debris from your dishes before putting them into the dishwasher.Pieces or bone and other debris will surely have you calling me for service. Also, be mindful of pots with handles and check them periodically for loose handle screws as well as labels that may come off during a cycle and clog filters causing poor cleaning.
Cleaning up any spills on the door and around the door gasket will ensure a good door seal.
Inspect the spray arm ports for lodged debris. This will also cause poor cleaning.