basically...
the CLD goes on panels that vibrate/reverberate. the "tap test" will show what needs a vibration dampener. the bigger the area, the flatter the area, the more it vibrates. the doors, for instance, are just a huge flat piece of metal. i do believe in the 25% coverage rule, but i think the front doors are the place to really go full out especially to seal them...if your speakers are there.
parts that are curved need less or no deadener. if its a larger area that fails the tap test, then apply some CLD. making a car look like the inside of a tin foil hat is really unnecessary as are like 3 layers of deadener. if you have a rattle that serious, time to break out the welder and some angle iron
dynamat doesn't block noise.
the CCF goes on next. its function is to decouple the MLV and provide a "springiness" to the MLV. CCF is also used behind panels or trim pieces to stop rattles.
then the MLV layer is last. this is the "noise blocker" that keeps out road noise. it needs to be (ideally) a single layer, unbroken, or properly joined. it goes on the floor, in the doors, and on the rear wheel wells in the trunk.
i really dont know why people always take so much time/effort/material to deaden their spare tire well, especially when the spare tire is still in there and secured down. the rubber is its own dampener. so much more noise is let in through the wheel wells. it gives me a
at least.