No one chest exercise works in complete isolation. You may be doing incline presses, trying to recruit more muscle fibers from the clavical head of the pectorals, but you're still heavily recruiting from the sternal head as well. Any chest exercise is going to recruit muscles from the entire chest. You alter the angle of the movements to target certain areas more, as in, trying to recruit more muscle fibers from that area. For example, on incline presses, you're more heavily recruiting from the upper pectorals than you would be if you were doing flat presses, but you're still recruiting a lot of fibers from the entire chest, as well as the triceps, deltiods, and so on...
So I wouldn't try to form a routine that trys to target each head independently, because that's not going to work. If you're going to work your chest twice a week, then work your "chest" twice a week. Something like barbells on monday, and dumbbells on thursday would work. I do the same routine on monday as on thursday, changing it up a little sometimes depending on how I "feel." And as long as I'm seeing results, then I'll continue on that route.
If you have any more questions, just ask! Good luck man!
