When I actually started measuring out what I ate, I was floored!!! I didn't realize how many servings I was truly eating! I now measure everything out and eat individual servings of all items and types of food. This alone has decreased the amount of food I eat.
I also have the tendency to stay away from junk food. Recently, I splurged and bought a "Big Size" fritos bag down in our cafeteria at work. Without realizing it, I polished the bag off. AFTERWARDS, I looked at the nutritional content and was stunned, there was actually 4.5 servings in that bag!!! If I remember correctly, there was 10 grams of fat per serving! EW! And yet we regularly eat one of these bags? I'll never make that mistake again!
So here's the tip I have learned to keep my portion sizes to one serving. Once I get home from the grocery store, I will break apart any big items into the correct number of servings. A big bag of baby carrots, a set of grapes, even Baked Lays! Everything gets bagged individually, that way, I know one bag is all I get at that sitting!