Bodyweight squats

Plant your feet shoulder-width apart and point your toes slightly outwards.
Optional – Elevate your heels on a pair of small weight plates to increase mobility.
Flex your core.
Breathe in and start bending your knees in a controlled manner for 2-4 seconds. Imagine that you’re trying to tear an A4-paper in half with your feet to avoid buckling knees. Your knees shall always point in the same direction as your feet.
Pause at your deepest point of the squat.
Push your feet through the floor and extend your legs to the starting position (90-95% straight). Breathe out when you reach the halfway point.