My previous post was about safe lifting technique. To do this, you have to be able to squat. We practice this in some classes and it’s a good exercise to do at home.
Stand with your legs apart, either parallel or turned out, whichever is most comfortable for you. Then bend your knees as deeply as you can, aiming your bottom towards the floor. It may help to hold on to something for support, and to lift you heels a little at first.
You can read more about the benefits of squatting in this Squat, Don’t Sit! post from a teacher of Alexander Technique.