For me, the key this time is exercise, I never used to be into it at all but this time I have turned it into a habit, and it feels like it's normal for me now to exercise 4 or 5 times a week, and then to keep active with things like walking every day. I haven't changed my diet too much, just smaller portions and aiming to eat more nutritiously as I know I won't get on with no carbs etc, so my weight loss has been slow but it feels like it's here to stay, before it was easy come easy go. So I guess my advice is to go slow and steady and also to never write off a day because you slipped, get back into good habits as soon as you slip - you had pizza at lunch, no problem, just do some exercise in the evening and have a light dinner, salad or something. And, writing down what you've done helps - exercise and food, then if you have good results you know what works for you. Good luck!!