Moist underneath and dry on top. To achieve that you really need deep layers of bedding, manure, bedding, manure until you have formed a "pack". This pack will hold moisture in the bottom where it can encourage bug, worm and microbial life to break down the organic materials there and this will also wick moisture away from the surface. To encourage this even further, you'll want to lightly cover or turn your daily roost droppings into the surface of the pack in order to give the bugs access to the feces...they don't like coming to the surface for feeding.
Now, sometimes your birds are going to rearrange that whole thing as they hunt through the DL for these bugs and that's okay...there's where your aeration of the mass will come in. People think you need to stir it up every day to get that but when you do that you are losing valuable moisture and disturbing all that life at the bottom layers. The chickens will plow through there every now and again, glean some bugs, air out the mass and then it will settle back down until it builds up more microbial life and insect life to continue the composting...it's a nice cycle and it takes time to get there but if you have patience and build your pack well, give your coop good ventilation to move the ammonia up and out and allow for the humidity in the air to absorb into the pack, then you can finally start to see a real DL system going on.
If you live in a very arid place, you might want to add your own moisture to the pack to facilitate all these things and you can also use bedding with natural moisture built in, such as grass clippings, hay, etc.