The 80/20 principle applied to diet

You probably heard of the 80/20 principle. It’s the principle that states that 80% of the effects come from 20% of the causes.
In other words, it means that a few inputs/causes/elements generate the most output/consequences/results.
Applying the 80/20 principle to making changes in your life yields the following insight: a few habits and practices you acquire will be inmensely powerful, while the rest of them will barely make a difference.
I have been trying to find those vital few habits related to eating that will make a huge impact on me. And these habits should also be easy enough to implement. Because if my habit were to be something like eat 2500 calories of paleo foods every day and nothing else, although simple and likely very effective, it would be absolutely unmantainable. Believe me, I tried.
There’s two eating habits that are really working for me. They are 1) easy enough to implement; 2) don’t take much effort to maintain; and 3) I can make exceptions quite often without sidetracking the process.
These are my two 80/20 eating habits:

IF has been very easy to do for me and it effectively allows me to slowly lose weight without having any other dietary restrictions.
Avoiding dairy is harder for me, but it has proven to be tremendously effective for weight loss and apetite control. I am now slowly adopting this habit again.
Besides these two habits, which may be useful for you, I would rather you explore your 80/20 actions regarding eating. They might likely be different from mine. What matters is that you look for them. Find something that’s easy to do (for you) and still very effective. Ignore the other ideas that haven’t proved themselves useful to you.
Eating habits are very hard to maintain. Demand an uncanny amount of return on investment for the effort you invest in them.
Eating should be something pleasant and healthy. If you can find a couple of principles that will really do the trick for you, it might be a far better investment than a strict diet or eating philosophy.