Most of the blood sugar meters and CGMS systems have software to let you upload and monitor your blood sugar. I've only use the lifescan software and Dexcom software, but have found them both to be not ideal. So I combined the data from Dexcom sensor readings (blue), lifescan BG readings (red), carbohydrate (up arrow), and insulin (down arrow) extracted from my LifeScan Ultra smart meter and added photos of my food (see attached graphs).
I collect this data the week before visiting my doctor and he says it is a fantastic way to visualize how different types of food affect my BG. I think it is a good way to see clearly the complexity of monitoring BG successfully.