I use the measuring cups and spoons, but my digital scale is a godsend for things like meat and bread. The calorie counter in my LoseIt app just says silly things like "one slice" -- what does that mean if slices come in different sizes? What if I just slice it really thick?! Woo hoo! Still only 100 calories!
So I have added in from other sources the values of chicken, pork, beef and salmon per oz, and several different types of bread that I eat per oz. It was really helpful to see what size one "portion" of chicken breast was and now I can estimate easily when I eat out.
On some packages now (especially in Europe) they will give the standardized amount of calories etc for 100g, and then the calories for a typical portion (like two bars in a double pack of granola bars). But not for everything, so for my whole kernel rye bread I have the 100g values entered under "one serving" and if it weighs as only 72g I can put in "3/4" for the serving and it automatically calculates it. I think other online calorie counters like FitDay do that too.
My scale can be switched between ounces and grams, so if you are in the market for one look for that. Mine wasn't expensive, around $20 I think, and you can get cheaper if you shop around. Most also have a "tare" function where you can put an empty container on and set it at "0" then spoon in your flour or whatever.