1- Start the movement by breaking at the knees first and not the hips, then sit back into the movement. This is probably the biggest mistake most beginners make.
They either do one or the other. They either start the movement by bending their knees first, and then never bend their hips. Or they start the movement at the hips and then round their lower back at the bottom of the movement.
Focus on moving the knees slightly forward initially, then sit your hips back into the movement.
2- Point your toes slightly out.
3- Open up the hips, track the knees outward- This is key, as by starting the movement from the knees first, you risk the knees being too far forward. Thus, focus on opening up the hips (track your knees out over your toes).
4- Proper dynamic warm up. Open up those hips and ankles. If you go to YouTube and type in “Bryce Lewis” he has some excellent warm up drills you can watch.
5- Look straight ahead. This is somewhat of a grey area, this may take some trial and error where you prefer to look, choose which ever feels best for you. I tend to find looking straight ahead is best. Most of the top powerlifters do this too.
6- Drive your feet through the floor- Imagine you are trying to push your heels through the floor, focus your weight on your heels/middle of your feet and not your toes.
7- Upper back tightness- Make sure your elbows are pointing down and not back. Imagine you are about to do a behind the kneck overhead press with the bar. That’s the elbow position you want. Try it now without any weight, you should feel how tight your upper back is.
8- Breathing- Take some big deep breaths before you squat.
9- Push your abdominals out- Keep your abdominals contracted and pushed out throughout the whole movement.
10- Mobility (ankle/hip)- Most people lack good squat form mainly due to poor hip and ankle mobility. Again, type in “Bryce Lewis” into YouTube for some good drills you can perform to help improve these.
11- Proper footwear-Avoid running shoes when you are squatting. You want something with a solid and raised heel. The problem with running shoes is that are unstable for squatting, as they allow for compression. (Good for running, not so good for squatting).
12- Depth- Ideally you will get to at least parallel to the floor. This is yet another grey area, as different people can achieve different depths safely. I would argue, get as low as possible while maintaining a neutral spine. I.e. not rounding your back at the bottom of the squat.
13- Low bar vs High bar squat. Low bar will put more stress on your lower back, but you will be able to lift more weight, I would suggest using a belt with this style. Higher bar, is typically better at stimulating the legs. This is what I would suggest for most individuals.
High bar- Positioned across the upper trapezius (Traps).
Low Bar- Slightly lower, approximately on the rear deltoids.
The image shows you the bar position for each