Seriously though... Been doing exercises that flex the upper/inner pec, like sitting 45 degrees in a hammer strength machine and pressing the weight across my chest and not coming all the way back to a full stretch.
Also sitting low in a pec deck machine and doing flies out in front of my face. Cross-over cable flies as well. Anything to get that v-neck cleavage!!!
In my day we finished with cross bench dumbbell pullovers, Arnold claimed that once he implemented this into his arsenal he gained 5 extra inches on his chest, and an awesome way to stretch out the ribcage.