Cut down on the sugar and salt intake, this includes those nasty dietary sugars. Sugar is bad for you, and dietary sugar is even worse! Salt retains water, which makes you gain weight. Please remember, you do need salt and sugar in your diet, you just need to cut down on it.
Cut out the soda, even if it is diet. It contains high amount of sugar and, if you think that diet soda is better, research has proven that it is actually worse than regular sugar.