Probably the largest single reason for excessive cracking in stucco is not allowing the brown coat cure long enough. These cracks usually look like the cracks of a shattered mirror. 
  Each layer of cement forms it's own separate slab. Only a slight amount of
cracking in the brown coat will shatter the finish coat. As the brown coat cures,
and dries, it shrinks and cracks. 
  In California, the building code requires the brown coat sit for 30 days before the finish is applied.(Correct me if I am wrong). This seems like an expensive delay in hot, desert areas where 2 or 3 days may be fine. Fortunately, here in Virginia, there is no building code governing stucco, which is both good and bad. The good is I don't have the government directing me how to do my work.
  Another good reason to let the mortar sit is to avoid being able to "read" green spots in the finish. You can see the size and shape of the green spot a long
way away. It ususally shows as a swirly or coarse area.
  The best thing to do here is do nothing- let it sit.