What are the main causes of dishes not drying properly?

Common causes include an empty rinse aid dispenser or incorrect rinse aid amount set, not choosing the Extra Dry heat option, water collected in depressions on dishes (arrange upper rack dishes to slope for drainage), opening the door before the cycle completes, plastics not drying as well as cutlery or china (use more intensive cycles or Extra Dry option), and improper silverware arrangement in the basket.