Everyone has their favorite exercise, drill, move, pose, etc. Mine is probably the barbell back squat. Ironically, it's one I've never been incredibly strong with. My form has always been solid but my weights never really exploded. Admittedly, when fully healthy, it was never move I ever tried to lift incredibly heavy on and usually kept my reps between 10-20. For a long, long time I've had some hip back issues and it's just not worth it.
However, even at the 10-20 range (or higher or lower) the overall benefits of this move are right up there at the top w deadlifts, similar move from the hips down but different load.
Big moves recruit more muscle fiber, build muscle faster, thus burning more calories 24/7, not just when training.
How to set up a back squat:
A) feet are set hip width or just a tad wider. You can go wider or more narrow but there is a greater risk and you could be putting your knees in a bad position. For beginners and beat odds of safety, hip width or slightly wider.
B) Set the bar across your upper back/traps (NOT YOUR NECK). Hands can be placed nearly anywhere along the bar as long as you have a firm grip, keeping it in position and so your hands/fingers are not in jeopardy of getting pinched/slammed when re-racking.
I have very tight shoulders so I set my hands as wide as possible.
C) Slowly start to lower your hips while keeping your chest up, exposed to the wall. I often say "I need to read your T shirt." This keeps people from leaning over and putting too much pressure on the back. So chest up, abs tight, as your hips lower.
D) Stick your butt back a little as if reaching for a chair. This will keep the midline of your knees behind your toes, maintaining a safe position and limiting strain on the knees.
E) Lower hips until comfortable. Ideally, your hips will drop as low as your knees. The side view would look like a lightening bolt with your upper body and shins at a similar angle, with your thigh parallel to the ground.
F) With eyes on a target, exhale and push through your heals until standing tall again. Do not lock your knees out.
Keys: eyes up, chest up, butt back, 1" lower, drive through the heals, breathe, focus