incline press
flat press
leaning forward dips
a flye motion -- flat or incline(keep in mind one of the functions of the chest is to bring to arms across the body)
mix and match these, go for bb or db, whatevs, and your set.
I'm definitely not a pro, but my chest is definitely one of my standout parts, very well shaped, and I have never gotten into declines, flat seems to do the trick for me, followed by lots of incline work