Six finger squeeze.

Without releasing the squeeze in your shoulder blades, reach your arms straight up. Rotate your thumbs in toward your feet until the bar crosses the meatiest part of your palm, inline with the center of the wrist. Note the distance between your hands, then slide them apart to increase that distance by half. Wrap your fingers around the bar and squeeze it as tightly as possible. Slide your thumb one finger-width in from your index finger as if to make room for one more digit, then try to bend apart the bar like a horseshoe.
Bar Placement
BULLDOG GRIP
BULLDOG GRIP
Barbell Medicine
LEGO BENCH PRESS
LEGO BENCH PRESS
You want to avoid excessive hyperextension of the wrist and you can correct this by thinking about punching the ceiling as a cue.
Jeff Nippard
We're trying to create the most supportive position possible, which is gonna be the forearm supporting the bar. So the bar's gonna go right through the lower meat of her palm (the lower third of the palm) and a slight cock back of the wrist is acceptable... which is gonna allow the bar to sit right on top of the forearm.
Juggernaut
Internally rotate your grip...and get the bar hooked deep in your palm... The bar is over the lowest portion of my palm/wrist.
Brendan Tietz
Stack the wrist joint in such a way that there's no moment arm between the barbell and the eight bones of the wrist and the radius. We'd like to carry the bar as high as possible from an anatomical standpoint - high meaning towards the wrists versus low which would be towards the fingertips.
Barbell Medicine
...take the bar low in the palm...[to avoid] putting the bar back behind the wrist... and I'll actually take a little bit of an internally rotated grip to get that weight on the right part of my palms where I like it. I'll grab the bar and I'll.. crank in so my wrists are now more...neutral as opposed internally rotated at the shoulder.
Calgary Barbell
It is common that lifters’ become too concerned with keeping their wrist straight in the bench press and in keeping an overly straight wrist the bar tends to hang in the thumb, rather than be supported by the forearm. A slight bend back in the wrist will keep the bar stacked over the forearm in a more supported and stable position.
Placing the bar through the thickest part of your palm will be the safest and best place to press from. Too close to the fingers will cause too much stress on the wrist. Too close to the wrist can cause a disastrous slip of the bar off the hand.
Once you’ve set your hand position, try and place the bar as close to your thumb as possible. This will help keep the wrist aligned in a neutral position, which will not only improve your performance but decrease the likelihood of injury as well.
Robertson Training Systems
Grip Width
GRIP WIDTH
GRIP WIDTH
Juggernaut
BENCH PRESS GRIP
BENCH PRESS GRIP
An important factor in determining grip width should be whether or not your joints are stacked from the rear position (meaning the wrist should be roughly positioned over the elbows)... A max width of roughly 1.5 times shoulder-width is best for reducing injury without seriously compromising maximal strength... Make sure you have your wrist joints stacked... directly below your knuckles.
Jeff Nippard
When the bar is on the athlete's chest, the bar is stacked right over the wrist, and the wrist is stacked right over the elbow.
Juggernaut
How wide you set your grip is going to be different for every single person because we're all built differently. That said, if you get a wider grip you will shorten the range of motion and that is a good thing. However, your shoulder risk goes up a LOT so wider grip I typically don't recommend most people do. Sticking your hands at the side of your shoulder is going to be throwing most that force on your triceps, and you're going to take a lot of your chest out of it. Which is like playing a sport with a man down, so it's not smart. If you're trying to bench as much as possible, you want to use every single muscle that you can possibly get. For most people, sticking your hands just outside your shoulders will keep your arms perpendicular to the bar running at a 90 degree angle - almost like pillars on a building. Pillars support weight, so I think that's probably the best option.
Neversate
Squeeze
SQUEEZE THUMB TO PINKY
SQUEEZE THUMB TO PINKY
Neversate
Focus on squeezing the bar a bit extra hard with your pinkie, and that's going to help create a little bit more internal rotation tension in the shoulder.
Juggernaut
Number one: I'm squeezing that bar as hard as possible... Your body works synergistically. If you cannot open a jar, squeeze the jar. Your body is like an electrical circuit; if you are not creating force everywhere that you can potentially create force, which includes squeezing your hands on every single lift, then you're leaving reps out there with unicorns and the ether.
Neversate
Squeeze the bar as hard as possible. This makes everything more stable, gives you a better bar path, and creates more shoulder stability via the irradiation principle. It'll also make the bar feel lighter.
One of the biggest aspects to benching huge weight is having an iron grip to the bar. You want to crush that bar for all it’s worth to get optimal muscular activation and to amplify the nervous system.
Squeeze the shit out of it. This will activate all the muscles in your hands, forearms, and triceps, and reinforce the tightness from your lower body and torso to the bar. You should be pretty damned uncomfortable.
SQUEEZE THE BAR. If you can un-rack the bar and still wiggle your fingers you aren’t squeezing hard enough. Squeeze the pinky side of each hand.
MPS Training
Squeezing the bar sends a signal to the rotator cuff – through a process called irradiation – to pack itself. This provides more stability to the shoulder joint, which is never a bad thing when you're trying to hoist heavy loads off your chest. Squeezing the bar can also help create a more beneficial wrist position. A neutral wrist can squeeze a bar much more effectively than a hyper-extended one.
Bend
BEND THE BAR TO FEET
BEND THE BAR TO FEET
Jeff Nippard
PULL THE BAR APART
PULL THE BAR APART
whiteboard_daily
CREATE FULL BODY TENSION
CREATE FULL BODY TENSION
Try to bend the bar like a horseshoe... You are not going to be able to NOT grip that bar as hard as you possibly can, and... it's also gonna lock in your lats, which is gonna allow you to keep your elbows tucked into the set.
Neversate
Grip the bar like you would in a traditional grip, but slide the thumb out. When the thumb is spread out from the other fingers, it is left to serve more as an anchor to allow you to bend the bar effectively, while yielding similar benefits from a false grip. It is a best-of-both-worlds scenario that works tremendously for lifters. Those having a hard time tuning in with their lats will benefit immensely from this grip.
...bend the bar apart to engage my lats better. Basically, think about externally rotating your hands as you bench. Once I was able to get the hang of this, I was able to engage my lats like never before. I felt much tighter, and the tighter you are, the safer you are, and the stronger you will be. Once I start to bring the bar down, I try to bend it in half and flare my lats as hard as I can.
Aim to twist their pinky fingers towards their toes. Bending the bar in this manner allows you to engage the lats optimally.