Generally a two day split routine with about 2 hours per session. I would generally throw my abs in at the end of a workout but found i wasnt getting the results i had hoped so then i dedicated actual 'ab hours' where i would do nothing but abs. I had to bring my legs particularly quads a long way as i was generally bigger in the upper body so i would often do 5x5 sets on squats with a post fatigue leg extension rotated with heave leg press and lunge days.
Also once every two weeks i would do a 10x10 sets to complete failure and that was painful! ANy particulars let me know