Walk everywhere. At least one hour a day. That alone will make a enormous difference. MOVE!

Cook the bulk of your food, don't eat out.

Eat a good healthy big breakfast so you don't pig out later from hunger. My breakfasts are HUGE. I had a weetabix with banana, a boiled egg, wholewheat toast, and apple and a yogurt for breakfast (I eat that over about an hour period, not in one sitting) and I am full of energy until about one when I eat lunch.

Don't buy into diet fads. Just eat veggies, fruit, whole grains, and lean protein. I doubt drinking green tea will make a huge difference in your metabolism and most people put either a ton of sugar or artificial sweetener in it. Water is best.