Definitely measure, use smaller dishes, etc. One of the big things is when you make, for example, a chicken breast - immediately cut it in half. One for now, one for later.
The more preplanning and "ahead of time" work you can do the better. If there are some kinds of treat foods you like to eat and can healthfully work into a daily menu, try and find portion-packaged versions of them!
Avoid buying in bulk, even if it's the portion package version of things. For example: if I have a box of 6 low-calorie frozen treat bars, that will last me one week. If I have a box of 24 low-calorie frozen treat bars, that will last me one week. Get the picture?
And of course - track everything!!! Good luck!