The biggest thing, for me anyway, was getting rid of the all or nothing attitude. I cannot count how many times I have gone absolutely hog wild because I woke up cranky, had more calories than I'd intended or eaten something "bad," and then said "screw it, I'm going to eat whatever I want for this ENTIRE DAY." What I realized is every time I think something like that, I'm making an excuse when really, I'm doing it because I WANT to. There isn't really an excuse.
So recognize that you don't have to listen to the angel on your shoulder 100% of the time, but you do have to reign in that devil on your other shoulder!
So many of us thing of weight loss as an all or nothing thing. But really, what it has to be is sustainable for the long term. The way I'm eating now is a way I can eat for the rest of my life, and that is absolutely key. If I go out to dinner and make a bad decision, that's one dinner. It doesn't murder every bit of progress and every other struggle. (And I do have that one dinner. Probably about once a week.)
Just keep your sights on the outcome you want! Also keep in mind the longer your diet hiatus, the harder it is to get back on the wagon. But at the same time, the longer you're on plan, the easier it gets. So it's worth it.
What you really need to do is find methods that work for you. Believe me, I've done this more times than I can count, and I feel that this time will stick because:
1. I exercise in the morning. Only one day has been terrible eating-wise because I don't want to backpedal on the progress I've made. It centers me.
2. Protein with every snack and meal. It makes a huge difference.
3. Limiting the carbs. I am a carboholic. When I have more, I want even more, and I'm hungrier. I'm not saying this is for everyone, but knowing your body and your patterns of hunger is a HUGE help.
4. Getting an idea of how much I'm eating without obsessing. I absolutely loathe logging calories etc. But every few days I'll do it to make sure I'm on track (for the most part, I eat very similar meals/snacks for a few days in a row, I'm big on leftovers, so I find that it's accurate without being overwhelming.)
Good luck!