The depth of the squat depends on the range of motion of your joints. Generally speaking, you can get up if you are at 90 degrees to the ground.
Look forward all the way, tighten the core muscles, keep the spine neutral and avoid bending.
In the process of standing up, the brain will imagine that the muscles behind the legs (biceps femoris) will start to exert force first. The key is that the force is transmitted by the sole of the foot, and the force exerted by the sole of the foot should be transmitted uniformly by the front and rear feet at the same time.
When the weight is low (15-20RM), you can exhale when standing, but when the weight is high (3-9rm), it is recommended to complete the whole movement before breathing.
The effect of squat hip lifting exercise is also very good. In fact, the effect of squatting on the ass is much better than that of biceps femoris.