The Plum Ginger Hibiscus herbal iced tea (previously mentioned) is a great mixer. I like it with a little sierra mist to sweeten it just a hint and give it a hint of citrus, or mixed with lemonade. I've mixed it with nearly everything else there, though, and found only one or two mixes that were on my 'maybe not to repeat' list.
I personally like to mix the Agave Lemonade with the... I think it's plum something? It's the darkest drink in their homemade mixtures.
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