Gain Weight, Set a New PR
What's the best way to increase your bench press PR? Gain weight. I've found this to consistently be the number one thing guys can do to increase their plateaued bench.
Despite all the talk about doing a bunch of repetitive triceps and back work, if your bench is really stuck, it's likely your bodyweight has been the same for a long time.
Don't believe me? Spend the next two months not giving a crap about maintaining a sexy body composition and eat until you hurt every day. Then watch what your bench press does. It'll skyrocket.
And Narrow Your Grip
Don't want to gain weight? Fine, bench with a closer grip. It allows you to get much tighter in the upper back, providing better stability through the shoulders and providing more protection for them.
If you've been benching with a wider grip, you'll take an ego hit because obviously you won't be benching as much as you had been before this switch. But rest assured, you'll eventually climb back to where you were. Your pecs and shoulders will thank you for it.