• Pre-plan:
• Know where you are going before you lift.
• Chose a clear path.
• Increase balance by keeping your feet shoulder width apart.
• One foot should be slightly forward.
• Take a deep breath, and tighten your stomach muscles before you lift.
• Bend at your knees and hips, not your waist.
• Lift using your leg muscles to reduce the load on your back.
• Lifts smoothly, do not jerk as you lift.
• Sudden movement and weight shifts can injure your back.
• Face the load you are lifting.
• Hold the load close to your body at waist height.
• Turn with your feet, not your back, to avoid twisting when lifting.

(Source: UCLA)