Things that need no cooking to be safe to eat (like prepared foods or leftovers) are placed at the top, then everything else is organized downwards based on the temperature it needs to be cooked to, with the foods needing to be cooked to the highest temperature (like chicken) being at the bottom.
When organized this way, any cross contamination that occurs won't be a problem because the food that's contaminated has to be cooked to a higher temperature than the food sitting above it that dripped down.
Leftovers, drinks, and ready-to-eat foods (like yogurt, cheese, and deli meats).
Raw ingredients slated for cooked dishes.
The refrigerator door is the warmest part of the fridge, so only condiments should go there. Don't put eggs or milk in the door, as they should be placed in a colder part of the refrigerator.
These can be tricky. Since they're designed to hold produce at specific humidities, it makes sense to store fruits and veggies there. But they're usually at the bottom of the fridge, so we risk contaminating our fresh vegetables if we put meat on the shelf above.
If you have two drawers, make one of them exclusively for veggies and the other exclusively for raw meat.
If one drawer is above the other, use the lowest drawer for meat. If they're side-by-side, either drawer would be fine. Clean the drawer you're using for meat often.
Need both drawers for fruits and veggies? If it's unavoidable to put raw meat above other foods, improvise your own meat drawer by using a clear plastic bin that will catch any accidental drips and keep the meat safely away from everything else.