If you have a puffy chest or flabby lower chest it is most likely due to two things: bodyfat % and of course genetics. I genetically have lower chest fat as well. If you want to lose it, lower the bodyfat percentage, meaning get on a strict diet + cardio. If you really want it bad,... youll go on a strict diet. Once you get your BF down to a certain point, if your diet remains constant, you shouldn't have to keep doing any cardio.
"Sculpting" wise,... keep the presses, and "brush" up as much as possible on form, and higher the reps, 10+. Add in some dips, and deep DB flys, and you should be good to go.
I think leaning out is the biggest improvement you could make right now,........if you are THAT concerned about the BF in your chest area.