Choose an appropriate weight to match your type of training and fitness level. Take a shoulder-width stance and grab the dumbbells. Straighten up your torso. Put your pelvis in a neutral position.
Step backward with one leg and lower your upper body down while keeping the torso upright and maintaining balance. Take the heel of your rear leg off the floor. Control the length of your backward step so that the knee angle in the lower position stays at 90-degree angle in both legs (between femur and tibia). Then go back to the starting position in the same way. Breathe in as you go down and breathe out as you go up. Alternate legs and repeat as required.
Maintain correct starting position and keep your torso upright. Conduct the backward motion along a virtual straight line from the starting position without rotating inwards or outwards. Keep control of your toes in the lower position for both feet as you step backward, i.e. both feet should be pointing forward. Do not allow your front knee to go forward beyond your toes.
Watch yourself sideways in the mirror to make sure you maintain the correct technique. Choose the resistance to match your abilities and fitness level. Start with lighter resistance to master the technique well.