Maintenance for me was a matter of testing out caloric intakes mixed with a static amount of exercise. This happens to be 16
calories per
pound given a 3-5 day exercise week.
As long as you're in the general ballpark, weight should maintain, assuming you're not always on the high side, lol.
Where people screw up is when they figure, "hey, I'm at my
goal, so I can be a little more lax." Said laxness turns into more and more cheats and more and more skipped workouts and sooner than later, what seems to be small deviations lead to large caloric surpluses... so much so that weight is regained.
And then you have people screaming about the stats that 97% of diets fail.
No, they work.
People just revert back to their original programming more often than not.