Quit soda is a pretty basic easy one. Don't drink anything except juices, water, and milk and make sure the juices are 0 sugar. You may get withdrawals depending on how often you regularly drink sugary drinks. Carbonated water works too, just make sure to read the label to see if it's actually 0 sugar. It'll take a lot of willpower in the first few weeks but after that it's smooth sailing. I'm 6 weeks right now without soda and already dropped 10 pounds of weight. All I've had is water, carbonated water, and lemonade on occasion.
Calorie counting can also help depending on the availability. You don't have to be meticulous. Just make sure you aren't eating as much empty calories and that you don't go over the recommended daily amount too much.