The three rules of building your chest
1. Do compound exercises
Choose flat and incline presses over flyes and cable crossovers. They allow you to lift heavier weight, thereby applying more tension to the muscles (and that means more growth).
2. Use progressive resistance
Do two or three sets of one or two exercises for the chest, and increase the weight you use or number of reps you perform each workout.
3. Improve your shoulder stability
The safest and strongest way to bench is with your shoulder blades pulled together and downward. Balance all your pressing work with rows, chinups, and cable face pulls to improve the shoulders' ability to retract.
The top three chest-training mistakes
1. Performing too many exercises
Don't burn yourself out doing pec-deck flyes in an effort to get a "defined chest". It won't happen. Instead, stick with the essential moves: dumbbell bench press, barbell bench press, dip, and pushup.
2. Lifting too much weight
For the most steady progress, add the smallest amount you can each session (in most gyms, this means two 2.5-lb plates, making five total extra pounds).
3. Poor bench press form
Always tuck your elbows close to your sides on the descent and touch the bar to the lower part of your sternum (this technique is great for guys with long arms).