Hey man,
Alls I do is bench press and wide dips. My outer, lower chest is much larger then my inner upper chest muscles.
I have gave up on flies, cables, etc.. and stick soley to bench presses (inc and reg) dips (wide) and pullovers..
I am doing HST 3x a week, 3 sets of bench, dips a week.. and my chest is by far the biggest muscle group in my body..