Hit the upper chest and build that top shelf.
Don't set the incline too steep or it turns into a shoulder press.
Setting the bench between 30 and 45 degrees points the pressing line at your upper chest, the stubborn shelf just below the collarbone that flat benching tends to leave behind. The pecs still run the show, but the incline recruits your shoulders more heavily to help drive the bar off the chest. It's the staple you add when your chest looks big from the front but flat from the side.
Start around 30 degrees. Every notch steeper shifts work from upper chest toward the front delts, and past 45 degrees you're basically shoulder pressing.
Almost everyone presses less on incline, and that's normal. The steeper line gives the shoulders more of the job and the pecs less leverage, so don't chase your flat bench numbers.
High on the chest, just below the collarbone. Letting it drift down toward the sternum turns the incline path into an awkward flat press and beats up your shoulders.
