1 bottle of Torani flavored syrup (usually in coffee/tea aisle)
2 liter bottle of Sprite (any brand works)
Quart of Half & Half
Pour half & half into a pitcher about 2/3-3/4 full. Pour in Torani and Sprite to taste. If you need more flavor, add more syrup and/or sprite, if you want it creamier add more half & half.
Good syrup flavor combinations: peach & vanilla or raspberry & vanilla, it tastes like peaches and cream, or raspberry cream. Or you can do flavors by themselves. Just play around with it. You can also make them individually in a tall glass if you are offering different flavor options. I get the Torani from Albertsons or Harmons. So far WalMart doesn't carry this brand. I haven't tried it with other brands.