I know this sounds like a gimmicky click-bait title, but there actually is one key technique that improves your balance, stability and force production in any exercise you choose to do at the gym.

The technical term for this technique is "muscular irradiation". It's actually a simple concept and you can see exactly how it works in the video below. Essentially it's the ability of one muscle to effective the amount of tension in the other muscles around it. When you flex any muscle strongly it will automatically improve your ability to tension nearby muscles.

Tension anywhere improves tension everywhere.

Sounds like some mystic teaching from a Shaolin monk, right? Again, it's all pretty simple and it's something you should use when lifting heavy weights or when you need more stability or balancing. 

In something like a bench press, squeeze the bar as hard as you can, squeeze your back to max, brace your abs, and push your heels into the floor like your life depends on it. Squeeze everything you can! All of this will lead to a stronger bench press. 

Or you could try to keep everything relaxed and lift like a wet noodle.

Naturally there are some activities where staying relaxed, at least in parts of your body, is key. Many movements (especially fast ones) in sport require the right timing of tension and relaxation to complete. And, if you're biking for example, you should try to keep your face relaxed. Tension there doesn't help, it only hinders your breathing and can make you feel a bit panicked. 

But when it comes to slower lifting and generating peak force, remember that you should be a tension factory operating a maximum output. Build as much tension as possible throughout the entire body. See how that changes your lifts.