Lie back and press two dumbbells up with your palms facing each other and the weights nearly touching throughout the movement, rather than the wider path of a standard dumbbell press. Keep your elbows tracking close to your ribs as you lower, instead of letting them flare out to the sides. That narrow path shifts more of the work onto your triceps while your chest still drives the press, and it demands more shoulder stability since the dumbbells can wobble more easily than a fixed bar. Lower until your elbows reach roughly chest height, then press back up, keeping the weights close together rather than letting them drift apart.