Some of the methods will work for some, and not others. In the long term, even for the those who find they work, eventually may succumb.
My advice is that it's a lifestyle choice. It's not a diet. It's a marathon, not a sprint. It's not about the 30 days to leanness, it's about being consistent month after month, year after year.
The biggest secret that I can give you is to burn the fat, and to feed the muscle (also the title of a popular e-book which I recommend downloading). By this I mean; exercise. When you start exercises, yes you are burning fat, but over time your body will start telling you what it wants and what it needs. If you sit on the sofa all day, it will crave sugar and junk food. If you're exercising consistently (read, this will not come in the first month, it's a slow psychological change), you will stop desiring the junk food.
In fact the thought of it, and sight of it in the supermarket, will make you queasy. Because you will not want to give up all the hard work and effort you have put into the gym. You will look at the results in the mirror, and realise that a candy bar just isn't worth losing all of that. And, as above, it will fail to satiate your body like it used to. This is one of the few ways to really change your tastes. Remember when you were a kid and you had a particular craving, and now you don't - i.e. vegetables used to taste really disgusting, now they perhaps bearable? Now you like, for example, the taste of olives?
The more sophisticated advice is to have a cheat meal once a week and eat whatever you want. Alongside this, you may choose to do carb cycling and carb tapering, basically restricting your carbs, for instance, for three days and then having a high carb day, then repeating. That's an advanced method. Then there's intermittent fasting - there isn't a huge amount of evidence of it, it mostly comes down to preference in how you like to eat and restricting your calories.