dropping pepsi is a good place to start.

I should note that I didn't stop drinking soft drinks altogether. I still have non-diet soft drinks when I go to a restaurant. Because the restaurants only serve diet pepsi or diet coke which both taste like panther piss. I just stopped keeping it at home and work so that I didn't "just drink it because it was all I had". Now I just drink a lot of flavored iced tea and various other diet drinks when I'm looking for something tasty to drink.