depends on I guess why you're drinking it. If it's for fizzyness, try to switch over to flavored carbonated water. If it's for sugar, switching to tea/coffee is a good way to control your sugar intake, where as you can't with sodas. No matter what you do, the key is gradually reducing and staying with the plan. Do not quit cold turkey.
Unsweetened flavored seltzer was what eventually helped me kick soda. Same sensations, some flavor, and it's more or less the equivalent of drinking water, in that it's 0 calories, 0 sugars and 0 sodium.
Of course, I later fell off the wagon, but I limit myself to one soda a day, if that.
My path of transition was to simply ban it from being in my house. I swapped buying 12-packs of soda at the grocery store with buying 12-packs of seltzer. Then I let myself have a soda if I went out to eat somewhere, and I've naturally cut way back.
The biggest revelation was how after kicking soda for a few months, caffeine went from having no effect on me to a MASSIVE effect. I used to be able to drink coffee and some Cokes, and still be drowsy. Nowadays, I drink one coffee and I'm WIRED. The one time I tried drinking a Coke within a couple hours of drinking my morning cup of coffee I was actually uncomfortably wired. It's to the point that I no longer have coffee with my dessert when I go out to eat, simply because I know I won't be able to sleep well.
