Drink Lots of Cold Water
First, drinking water keeps your system clean and active, thus keeping your metabolism moving. Drink lots of it. Whatever you drink now, double it. Water has no calories; however it takes calories to digest. Further, your body temperature is around 98.6 degrees. It will do whatever it has to in order to stay there also.
By drinking cold water, your body will have to expend energy (calories) to bring this water up to 98.6 degrees. So opt for ice cold water if given the option. This isn't a game changer, but as Al Pacino said in Any Given Sunday "You find out life's this game of inches....when we add up all those inches, that's gonna make the difference between winning and losing."
Pick Snacks That Work for You and Not Against You
Negative calorie food is a food that is purported to require more calories to digest by the human body than it provides to the body by eating it. While there is no concrete evidence that this is such, there are multiple fruits and vegetables that are borderline negative calorie that make for excellent snacks.
These are broccoli, celery, lemons, limes, asparagus, mandarin oranges, cabbage, watermelon, peppers, carrots and apples. While these may not be negative calorie foods (depending on your metabolism and density of the specific piece of food) they are ultra-low calorie and ideal snacks. They will both take up space in your stomach and quench your hunger with virtually no penalty of ingesting unwanted calories.
Lift Some Weights
Perhaps the best way to increase your metabolism and burn fat is to build muscle. Muscle is catabolic, meaning it burns calories even when it's not doing anything.
If you don't already, add some challenging weight training into your routine. You may put on a little muscle weight, but you will now burn more fat and calories and look phenomenal. Stick to free weights when you can as these build more and in less time than guided machines.
Overall, losing fat is a collaboration of several different aspects at work. Incorporate all five of these tips for a couple months and you will be pleased with the results.