• Bend those knees to reach down or pick something up, whether you’re at work, at home, shopping, or wherever.
• Maintain a suitable posture at all times (sitting, driving, even when you’re looking down at screens). 
• Move your feet to turn when standing rather than twisting your back (retail workers get taught this nowadays).
• Be careful with other twisting motions, such as checking the traffic behind you (especially when doing it frequently as you do for a bike).
• Look after your general bone health (and density) with good nutrition, regular small doses of Vitamin D, and exercise.
• Do exercises that help improve your core strength and stability.
• Use the correct form when lifting weights or doing other exercises. Seek the services of a qualified fitness instructor/trainer to learn this if you are inexperienced.
• Your footwear may be the cause of (or a contributing factor to) poor skeletal alignment that leads to back problems. If this is the case a podiatrist can help.
• Maintain a healthy body weight. Argue all you like about the root cause (poor posture, not bending at the knees, strain of the weight itself, lack of exercise, poor nutrition, other associated bad habits), the undeniable fact is overweight and obese people are more likely to suffer back pain (and other joint pain).
• Don’t use back pain as an excuse to not exercise. Some rest is good (as necessary), but prolonged inactivity will just make it worse. You may need to change what you do for exercise though (at least temporarily).
• Pay attention to any mild pain you do have. Treat it as the early warning it is and don’t push your luck with bad habits.

If you do notice something that gives you cause for concern, go and see your doctor.