At some point it will become second nature. In situations where it is not practical to use a scale, for example, you will be able to make a good guess -- three ounces of cooked meat is about the size of a deck of cards or a cell phone.
I have an excellent digital food scale. It is probably the single most used tool in my kitchen, stove included. I also went to the trouble to measure the volumes of lots of regular things: my little "ice cream" bowls are 1 cup. my table spoons are, wow! one Tbps and my teaspoons are one tsp. My ice cream scoops are 1/4 cup for the black one and 1/3 cup for the green one. I now know.
Taste of Home has a pretty good guide here: www.tasteofhome.com/Healthy/Live-Well/Smar
for eyeballing different portions. Google "portion sizes."
I do some carpentry. "Measure twice, cut once." I would never think of doing anything else. OK, OK, OK. I exaggerate. The truth is I often pick up the saw and I have to REMIND myself to check my measurement. I don't consider myself in a rut there.
When I drive, I check my mirrors, my speedometer, my distance to the driver in front. I am constantly measuring. I don't consider myself in a rut there.
When I am in my kitchen, I measure everything when I cook. It's not in a dieting rut.
No one has to see you doing it anywhere but your kitchen. And if someone makes a remark, don't be embarrassed at what you are doing. They are rude and *they* should be embarrassed. You are taking control for a whole new you. You are taking responsibility for your actions of the past that got you to the point where you need to lose weight and you are changing them.
Grabbing a big bag of chips and eating them mindlessly while watching TV got you where you are. At first you will have to measure that 1.2 oz of chips. Eventually you will know what that looks like (and periodically you will want to check yourself for portion creep). Or better yet, you will skip the chips and grab an apple a a tablespoon of peanut butter to nosh on.
You aren't dieting. You are developing new habits.
I was recently out to dinner with my sister-in-law. I ordered a house salad, a cup of the broth-based soup, an extra portion of vegetable, and the entree. She looked at me and said something I know both our mothers' said to us. "You eat all that first and you won't have room for the main meal." I scooted my chair out just a little, put my hand on my now-athletic abs and said, "My dear, how do think a man like me got to be a man like me?"
I live in Baltimore, so you know that sometimes I just gotta have the cream of crab soup. That's part of not-dieting. I don't have it all the time. Usually I have the Chesapeake Crab soup, which is a vegetable/broth-based soup. But sometimes ....
FYI, I lost 90 pounds over an 18 month period beginning in April 2008 through Weight Watchers using EXACTLY the same principles that SparkPeople teaches. I have maintained since October 2009. About the same time that I reached goal, I became an adult-onset athlete. I am 58 years old and I just completed my first marathons, and triathlons.
Start by doing what is necessary, then do what is possible and suddenly you will be doing the impossible -- St Francis of Assisi
Rock 'n' Roll Dublin Half Marathon, Dublin, Ireland, 8/5/2013 ie.competitor.com/dublin/