Here you go Fl3wk, a quick explination >>>

STEP 1 >>> Get a ratio for your composition and stick to it. This is really important as you can’t just work in different size frames and expect your results to fit together, time and time again.
STEP 2 >>> Draw your first line. Horizontal or vertical makes no difference. But just remember that your first line is actually your 5th. What that means is that your “first line” sits in relation to your frame of 4 lines that you have established. This makes it your 5th line really.
STEP 3 >>> Draw your dynamic diagonal line from 1 extreme corner of the compositional frame to the other. This could have been put in either direction and is your choice entirely. (STEP 3a.)
STEP 4 >>> Draw a horizontal or vertical line through the intersection of your two lines within the frame. you have now subdivided the frame in an informal way. (formal would mean you put your initial horizontal or vertical line in either the halfway point, at the quarter mark, or third of a way through your frame.)
STEP 5 >>> Sub divide your resulting boxes with another diagonal - this could have gone in numerous places, but it has to go from corner to corner within a box in the frame.
STEP 6 >>> Sub divide at an intersecting point again, with either a horizontal or vertical line. This makes more boxes again.
STEP 7 >>> Repeat the drawing of a diagonal within the new boxes.
STEP 8 >>> Keep going in this fashion, breaking up the space with diagonals to the corner of boxes, then laying in a horizontal or vertical at an intersecting point, until you have come to a satisfactory break up of space.
This is Loomis’ informal sub division technique as I understand it. I hope you find it a useful addition to your composition armoury. He loved it, and relied upon it to come up with ideas that were interesting and fresh. Download the books that Igor Sandman has posted up in that link if you want to know more about this great illustrators working methods! It’s all there in his books!! 
Cheers
MIKE 