The chest is probably if not the most popular muscle of the human body. You always hear the questions, "what do you bench?", "what's your bench max?" The chest is a magnificent muscle which happens to have 5 parts( upper, lower, middle, inner, and outer). Everyone looks at this particular muscle, we all want it, whether you're an athelete, average joe, weekend warrior, body builder, female, male, whoever. The chest muscle is a fan shaped muscle, which makes it so amazing, you would know what I mean if you've seen a medical chart of the chest. OK I'll stop babbling, how do we build these different parts of the chest? I will break down the parts and list the different exercises for them and then share what I do for my chest workout.
Upper chest: any type of incline movements(incline barbell presses, incline dumbbell presses, incline flyes-dumbbells or cables)
Lower chest: any type of decline movements(decline barbell presses, decline dumbbell presses, decline flyes-dumbbells or cables, dips)
Middle chest: any type of flat presses(barbell bench, dumbbell bench, dumbbell flyes or cables), however on dumbbell flyes I stop when the dumbbells are just above my chest 10-12 inches apart at the top of the movement, because I don't feel it neccessary to come together on this exercise but I do bring them together or even cross them on cable flyes.
Inner chest: close grip presses, dumbbell presses, it's tricky with dumbbells, I hold the dumbbells palms facing each other so the dumbbells touch each other and press them that way, also hits your triceps too, dumbbell or crossover cable flyes.
Outer chest: wide grip presses, incline, flat, or decline, with dumbbells I keep my hands wider than normal at the top of the movement just to target the outer part more. Flyes, incline, decline, flat, with dumbbells, I follow the same concept mentioned earlier, I don't bring them together but I do on cables.
So there are the exercises, now let's put them together and develop a workout for the chest.
First week and the second week are different for me. My first week goes like this:
Week 1: flat bench 2 warm-up sets of 15 reps
1 set of 12 reps
1 set of 10-12 reps
1 set of 8 reps
2 sets of 5-7 reps
3 sets of DROP sets
incline bench
1 set of 10 reps
1 set of 8-10 reps
2 sets of 6-8 reps
flat dumbbell bench
1 set of 10 reps
1 set of 8 reps
2 sets of 6-8 reps
flat dumbbell flyes or cable flyes
1 set of 20 reps
2 sets of 12-15 reps
dips
3-4 sets of 20-25 reps
Week 2: incline bench 2 warm-up sets of 12-15 reps
1 set of 12 reps
1 set of 8 reps
2 sets of 6-8 reps
3 sets of DROP sets
flat bench
1 set of 12 reps
1 set of 10 reps
1 set of 8 reps
2 sets of 6 reps
incline dumbbell press
1 set of 12 reps
1 set of 10 reps
2 sets of 8 reps
2-3 sets of drop sets
incline flyes(sometimes dumbbells or cables)
3 sets of 12-15 reps
dips
3 sets of 20-25 reps

My body responds better to higher volume, I only train 3-4 times a week twice a day. My Monday workout- chest and back
Wednesday workout- all legs
Friday workout- shoulders and arms
Every other Saturday Deadlift and some legs.
My first session I train 1 body part and and the second session I train the other body part. I'm going 85-90% of my max on most of the lifts, so training this way, I should get plenty of rest and recover when I train again. After 6-8 weeks I'll switch it up again, this is helping me put on size right now.
Remember "it's not how many hours you put in, it's what you put in the hours." And always choose the Correct Training Regimen and train to succeed.