Pump up your pecs by keeping these rules in mind.
1/ Do rows
Bent-over and dumbbell rows build the upper back muscles, keeping them in balance with your pecs. Your chest won’t grow if the body senses imbalance, so do as much work for your back as for your front
2/ Do suspended flys
Forget lying on the bench. Use gymnastics rings or a suspension trainer such as the TRX and perform a fly motion. Moving your body weight through space rather than moving dumbbells activates more pec fibres.
3/ Use less of an angle
Most guys do incline or decline presses at too steep an angle, transferring the stress of the exercise to their front delts and, worse, their shoulder joints. Use a shallower angle of 20-25 degrees to work the pecs more safely and directly.
Pulling a new bench max
Flare your lats as you bring the bar down. It should end up at your chest as though you pulled it there. Try to bend the bar by rotating your wrists outward (think about snapping a twig). It will help you generate more force — involving more muscles for maximum heavy lifting.