Hi there. You didn't give any details about yourself so I'll give the most basic and healthiest steps for anyone, diabetic and non-diabetic.
Drink water. Make plain water your main fluid intake and drink it regularly through the day.
Exercise regularly. Keep your body and heart active and your weight within the medically recommended range for your height.
Here is a helpful weight calculator: http://www.halls.md/ideal-weight/body.htm
See your family physician regularly, at least once a year, and get blood tests.
Limit or avoid white products: flour, sugar, rice, potatoes. Replace white bread with whole wheat, white rice with brown/basmati, sweet potatoes when possible.
Limit or avoid junk food, fast food, and other sources of empty calories and saturated fat. Cook at home more often to control what goes into your meal.
Limit or avoid deep fried foods and other unhealthy cooking methods that contribute to weight gain and cholesterol elevation.
Reduce or eliminate your alcohol consumption.
All of these combat the dangers of the sedentary no-exercise empty-calorie/simple carb North American lifestyle, a great contributor to diabetes. Whether you might have it or do have it, these can all help you manage your blood sugar better.
Diabetes onset, and the problems associated with existing diabetes, are reduced or prolonged by being healthy, active and fit, and eating a wholesome diet. In short, what every person should strive for if they can. Since diabetes can hit you at any age, it's never too late to start.