Want to maximize chest recruitment? Do 5-angle flyes.
Various angles of adduction are necessary to maximally recruit the pecs from the clavicle to the sternum. This exercise will hit most of them to stimulate new growth.
As you fatigue in one position, adjust the angle to a new position: high, mid, low or someone between those angles. You can even go back to a previous angle. This also allows you to extend the time under tension, one of the key components of hypertrophy training.
If you've been around weight training for any length of time, you've probably read or tried an arm specialization routine. There are a bunch of these around with different cool names for what amounts to the same old shit: do a bunch of arm exercises. Yeah, the exercises change and the sets and reps change, but it still amounts to just doing more arm work.
Has your bench been stuck so long you've considered loading up the bar to your usual weight and just welding the damn plates on? If that's true, it's time to bust through that pesky plateau.