Get The Right Footwear 
Wearing appropriate footwear helps to support your body and avoid injuring your knee, especially if you have a job where you are standing a significant amount of time. Over time, poor support can contribute to knee, back and foot pain. Find a store that specializes in supportive footwear and have them analyze exactly what you need. They are trained in knowing what times of shoes will fit best with the arches of your feet and your pattern of walking.

Use Fatigue Mats
Fatigue mats are great for anyone who is standing consistently whether that be at your occupation or if you are in the garage working or the kitchen cooking. Those hours of standing can put stress on not only your knees, but also your feet and back. If you are standing on a hard surface there is no flexibility, so consider a fatigue mat to help with knee pain before it starts.

Exercise
Maintaining a healthy weight and exercising regularly is a great way to prevent a knee injury from happening. Aerobic/cardio exercise is a great way to control your weight and also keep inflammation in the joints down. Consider doing yoga or stretching to keep your joints flexible and lubricated. Strength training is a great way to keep your muscles strong enough to support your joints.

Be Careful Of Overtraining
Exercise is important in living a healthy lifestyle, but preventing a knee injury is also important so be sure you do not overtrain and cause a knee injury. Changing your workouts regularly can help reduce the risk of knee injury. Also incorporate exercises that are easy on your knees such as yoga or swimming. If you start feeling pain in your knees when you are working out, stop what you are doing. If you push to hard you could cause a sports injury which would keep you from being able to exercise.