When there's physical work to be done, try to give the smaller joints of your body a nice break while your big joints swing into motion. They're big for a reason, after all. If you were to see a knuckle joint and an elbow joint side-by-side and had to choose one to pick up a plastic bag full of frozen groceries, you'd wisely go big, and so you should in your everyday life. If a bag or purse has a shoulder strap, see if you can "hook" it with your forearm when you pick it up, instead of clutching at it with your fingers. Also, hold it close to your body if possible instead of suspending it out from one side of your body.
When lifting something from the ground, bend using your hips and knees to protect the vertebrae in your spine. If a department-store door needs pushing to open, put a shoulder or hip to it. Use your foot or your rear end to shut the refrigerator door or clothing drawer.
If you can't go big, use tools or instruments to take the place of a larger joint. For example, instead of grabbing small drawer handles with your fingers, attach a loop of cloth or string to the handle so you can use your forearm for the task.