My mother-in-law and her new husband had almost this exact dishwasher and they hated it. Granted, neither of them know how to load a dishwasher worth a flip, let alone know the ins and outs of operating it properly. Still, try as I may to help them correct bad habits, it still wouldn't clean well.
My biggest pieces of advice for them were to use a high-end detergent like Finish Powerballs or Cascade Complete/Platinum, ALONG with a rinse aid in the dispenser. They seemed determined to buy cheap store brand LIQUID gels, a huge no-no in any machine, period. Also, these machines are very finicky when it comes to solid food particles, so the best defense is to use a silicon spatula or something to squeegee the dishes off before loading them, that way there isn't water being wasted to prerinse them, but you're also making sure that only water soluble soil is left on. Silverware is especially crucial to keep separated by the dividers in the basket; for some reason my mom-in-law seems determined to flip up the dividers, and cram and handful of silverware into a single compartment FACE DOWN (nearly gives me a heart attack everytime).
Other than that, the only thing I can think of is to use a heavy cycle or add Hi Temp to the cycle whenever there's more than just some residual liquid soil or something on the dishware.
They only had that machine for about 6 months before finally taking my original advice and getting the Maytag they have now, which performs beautifully in spite of their lack of skill when it comes to operating a dishwasher.