I've been very lucky in life and never had to diet. That said, I eat responsibly - I don't eat gigantic portions, I try not to snack too much, and I exercise.
There's a lot of evidence out there that dieting doesn't even work, so trying to find a good method is a lost cause. Your body needs less food that you think it does, so it's all about portion control. Obviously, you need to burn more calories than you take in in order to lose weight. Taking a good walk after dinner can help. Experts say light to moderate exercise, like walking daily, can be just as effective as more intense exercise.
But, in order for you to succeed, you can't completely deprive yourself. You can't completely purge the foods from your diet that you enjoy: pizza, beer, ice cream, potato chips, whatever. That's another way to set yourself up for failure.
OK, maybe I'm really lucky -- I'm in my early 40s and still have a metabolism in high gear. A year ago I had my cholesterol check and it came back the stellar results, low numbers of the bad and high numbers of the good. I told the nurse practitioner that I was a bit surprised that they were so good given that I eat 2-3 pints of Ben & Jerry's Ice Cream (yes, ice cream -- not frozen yogurt) each week. She told me I could eat more than that. I was a bit stunned as the doctor walked in. I asked him the same question, expecting he might steer me in another direction, but he said, "Hey, if you got it, enjoy it while you can." So, for now I am!