I usually start by blacklining (this can take a while so be patient) the entire model and painting black into all the recesses. The alternate and slightly quicker method would be to wash the entire mini with black so that it will automatically settle into the recesses and do the blacklining for you...the flip side is that it will also darken the entire model, but not usually enough to diminish the returns on the white too much. You\'ll still need to manually paint black into the deeper areas that will be in shadow but if it\'s not a competition model or one you are looking for display perfection on, this is a time saver.
Then paint as normal.
Hope that is helpful.