It is interesting, to me, how you get a full piece done at a time; I always want to have the whole thing laid out before I make any strong lines, and even then I continue to skip around all through the process. To do something like this without a guide or any apparent errors along the way is quite special!

I think you are doing it the right way. It's always about blocking the tones first then adding details and correcting any discrepancies. I however, can only concentrate on one small area at a time, and because of that, the gestalt of my compositions always suffer. It's going well enough this time because from time to time, I check how the levels work with each other from object to object, and apply some tonal corrections.