We actually made two bottles using different methods. Here are the two methods we used:
The flavoring syrup
For this one, we took all the ingredients in the original instructions, but we dissolved the sugar on the stove until it was a syrup, than we mixed the rest of the ingredients (plus a packet of Maltodextrin To make it thicker) into the syrup, and poured the syrup into the bottle along with about a liter of water.
For this bottle we pretty much followed the instructions on the website. Also, we didn't add any Maltodextrin.