My left pec is a little bigger than my right, mainly the inner upper area of the pec about an inch out from the center. Its a little beyond the area trained by cable crossovers or flyes. what should i do? incline dumbell press with just my right arm? please help me out.
We all have minor abnormalities. I know its hard not being perfect 
Anyway, use dumbells exclusively for chest movements. Its far too easy to not train your smaller side with barbells, machines and in some cases cables, unless you do them one hand at a time. Good Luck.
Is your right shoulder lower than your left(its typical for the dominant side to be a little lower) if its more than an inch or so it could change the look of your pecs,in that case you would have to work on balancing the musculature
of the shoulder complex to enhance your posture.
my right trap is a little smaller and then mainly the upper inner part of my right pec. i think ill just throw in a set of one handed incline dumbell presses on my chest workout and then some extra trap work.
Stand with your back against a wall ideally in front of a mirror or you can have someone observing for you. Keeping your glutes,shoulders and head against the wall raise your hands over your head without arching your lower back,if your reach is the same on both sides your ok, if your left hand goes higher than the right that would indicate the shoulder is more anteriorly rotated and stretching your lats and pecs along with following Cheks Shrug suggestions would help bring about balance.