from always being skinny and to finally just start working out seriously for the past 3 months, my chest still doesn't have that full shape. the very bottom of my sternum has no muscle on it and going upwards, there are a few lines that start around the breast plate. im guessing its the ribs that connect to the sternum? i have been neglecting decline and did mostly incline and flat db presses last month. i plan on switching to just incline and decline db presses this month to see how that goes. is there anyway i can get rid of these lines? fill them up to have the 'perfect' chest? what other work outs are recommended? is it better to do decline db press or dips? to give you a picture on how i'm skinny, i started at 155 standing at 6'1. i am now currently 165 and my goal is 185 by mid summer.