I love, love, love the way Precision Nutrition encourages us to keep track of our portions! It's so simple! No more complicated math or tedious in-putting of numbers and measurements to apps or journals.
All you need is your hand!

Check out the full article here: https://www.precisionnutrition.com/calorie-control-guide-infographic
So when I'm tracking (and I'm not always tracking, though when I'm working towards something, I tend do do better when I am tracking...), I use this very scientific method:

I just jot down what I've eaten for each meal (here I'm using my planner, but I sometimes use a notebook where I'll write down workouts to do or that I've done). Then, for each meal I write down how many of each category I've eaten. P= palm of protein, V= fist of vegetable, C = cupped handful of complex carbohydrate and F= thumbs of fat. So this day I had 5 palms of protein, 4 fists of veggies, 3 cupped handfuls of carbs and 4 thumbs of fat. I don't know what that 150 means, BTW. It's unrelated to the food :)
It's NOT exact. But it IS sustainable. For me. I don't do this everyday, but I could.
I just love that it doesn't feel restrictive to me. Instead it's just an opportunity every day. A challenge, if you will. How can I get 4-6 of each of these things?
I challenge you! Could you try this for a day? See what happens!