I want to build up my upper and inner chest, should I do incline presses and cable crossovers for this?
YES! As well as flat barbell presses, decline barbell presses & dumbbell flyes.
I do not say this because any of those exercises will actually target any specific region of your pectorial, cause they will not. I say this because to obtain "complete" chest development to your maximum genetic potential you will need a variety of exercises.
A common mistake people make is the "I feel it" syndrome. They think because an exercise makes a certain part of a muscle sore it must target that area of the muscle. This is true in some cases such as the deltoids where there are more than one head with different tendon attachments. The pectorial major is a single muscle with one tendon attachment to the humerous (arm) that fans accross the rib cage. However, it is still a single muscle and muscles grow as a whole, not in parts. Think about it this way, if you could cause growth in one area of a single muscle that would inply that it's possible to shape a muscle, right? Well, we all know (at least I hope we do) that you cannot shape a muscle. The shape of your muscles are genetically predetermined.
Now, it's still important to use multiple angles to hit the pectorial muscles (and any muscle for that matter), not because it will cause growth in one area, but because using different angles to hit a muscle is necessary for maximum stimulation and to continue progress and development.