The pectoral, or chest, muscles are the first area of the body after the face that eyes are automatically drawn to. They are the fan shaped muscles that cover the upper ribcage.
Technique is key to optimizing your training: it is essential in any exercise situation that you perform the movements correctly. There are certain muscles in the body that are not used on a regular basis, and/or are used differently than they would be in an exercise situation and the pectoral muscle group is one of them. Among the things you can do to first prepare them is pushups or, if you belong to a gym, the pec deck and chest machines are good to start with.
These machines are designed to limit your range of motion, thus focusing the unused muscles or getting them into action. Only when your muscles are at a point where they feel more stable and you feel comfortable should you upgrade to working out with free weights, dumbells and barbells, on a bench press--generally the flat bench is the bench to begin your free weight training on.
3 to 5 sets of repetitions of 6 to 12 during a workout is most common. Increasing and decreasing the weight between sets is best to develop strength and size rapidly. Once the muscle group has become more used to free weights you can move on to the other benches such as the incline bench, which develops the upper area of the chest, or the decline bench, which gives lift and width. The pec-deck, or flys, will help develop the centre giving a valley effect between. This, coupled with a high protein diet, will get your tighter-fitting shirt right where you want it.