When I make my shakes, I start with vanilla flavor and add root beer flavoring. I can usually find it in the cooking aisle, at HEB. If I have been Really good, I add 2 Tablespoons of Breyers Carb Smart vanilla ice cream. With that added, and the flavoring, it is a lot like a root beer float. I don't miss other sweets, this way, when on my plan.
@LittleTexas : I've been adding caramel flavored Greek yogurt to mine from time to time.