1) Dumbbell flys.

Another one of the most common types of exercises used to develop the mass of the pecs. The subject lies on a horizontal bench holding a dumbbell in each hand at arms length above the chest, palms facing each-other. He/she then slowly lowers them to the sides, until the point the pectorals are stretched out completely. Pausing for a second he/she then lifts the two dumbbells back to the starting position in an arc-like movement holding the arms bent a bit at the elbows in the “barrel-hug” position.
Extra considerations:
- you need to execute the movement strictly, do not bring the weights in and then push them upwards.
- flexing the pecs a bit at the top of the movement is always a good idea.