Olivia -- my cousin has maintained for a very long time and what she does is eat healthy "most of the time"
She has lost over 100lb with FAA and maintained for about 5-6 years
When I've had dinner with her, although I tend to show a complete lack of self control, she will order a salmon dish or some version of a protein and veggie dish. She tends to try to eat healthy most of the time if a healthy option is available and I've actually been trying to do the same.
There are also certain things she just DOES NOT do anymore, so her "falls" are not as bad as they used to be i.e., she no longer loads her Chipotle' meal with guacamole, cheese, sour cream...she just doesn't do it anymore. She has developed some healthy habits over time.
Also if she has a carb crave, she may "binge" on good veggies and the like until it passes or go vegan for a few days
As for myself, I am trying to develop a list of things that I will no longer do. The reality is -- life happens -- and you have to figure out what works for you.
My short list: :-)
--Protein drink before any events or parties
--$3 limit IF I end up at a fast food restaurant
--If I get weird cravings, I prepare a lobster/crab dinner at home
--Try to eat protein and veggies most of the time
--fill up on the good stuff first