First of all, it's hard to tell you what you should be doing since you haven't said a lot about yourself. However, here are some general guidelines:
First, if you are overweight, lose it. This will make your body more sensitive to the insulin you are producing resulting in better blood glucose levels for you.
Second, if you do not exercise, or do not exercise enough, start. Exercise is a great way of keeping blood sugars in line, and it also aids in weight loss.
Third, eat lots of fresh fruits, vegetables, and whole grains rather than their refined counterparts. Fibre, found in high quantities in these foods, helps prevent a rapid rise in insulin needs after consuming them. Refined carbs, like those found in cake, donuts, white bread, etc., tax the pancreas.
Four, avoid regular soft drinks, fruit juices, etc. The sugars in them enter the system very quickly forcing the pancreas to work harder to keep up with the task. Wherever possible, drink water and eat whole fruit rather than juices.
Well, that's a start. For further info regarding your particular case, it would probably be helpful if you see a dietician or your GP.