Here is my secret to every diet success I've had. Eat less. Exercise more. Continue until desired weight. The rest is crap.
That's really the short answer, isn't it?
I always thought of it as a 10-10 rule. Reduce caloric intake by 10%, and increase caloric burning by 10%, and you really tip the balance the other (good) way.
I would also recommend the 10% caloric intake reduction come off the top of the bad foods list - greasy stuff (Five Guys, breakfast meats), sugary stuff (sodas, candies, etc.).