Welcome, and you ask a very good question. When I first started serious low carb, I was more analytical and scrutinized what I ate much more closely than I do today. Make sure as you eat "prepared" low carb foods that you read the labels closely. Some of the usual suspects like Atkins Nutritionals can contain some ingredients that undermine certain individuals. Don't believe that it's low carb just because the package claims it.

The difference today is that I have been eating this way for so long, I know the whole foods I eat no longer require my scrutiny because they are healthy (nutrient dense), contribute very few carbs, and I have a solid history of achieving good health by eating this way consistently. I do not put a limit on how much I eat, as I now have a very strong "full" signal and do not desire to eat any more once I get that signal. If you're consistent with your approach, you will adapt in the same way. It really becomes low maintenance, but to do it correctly, and that varies a bit by individual, you need to apply more scrutiny to what goes in your mouth in the beginning. If done right, you'll reach your weight and health goals. It's a journey, and a commitment to enjoying it while learning what works for you is very rewarding.

ETA: clarified that I don't put a limit on "how much" I eat, I certainly follow specifics on "what" I eat.