That recipe is natural flavoured syrups. We're going to cover two types here: infused syrups and juice-based syrups. These are also going to be simple syrups - equal amounts of water and sugar by volume. (Though this measurement is skewed to more sugar-heavy when using juice.) I prefer this ratio because it's easy to measure, keeps well in the fridge, and has almost always worked well in mixed drinks, flavoured lemonades, sodas, and as tea sweetener.
I first started exploring domestic skills by making my college boyfriend snacks and birthday cakes. I was a firm believer in using the best ingredients and making the whole thing from scratch, but being the homemaker for our family has grown a new appreciation in me for accessible, shelf-stable ingredients and box mixes. Like my mother before me, I've found the best quick-made food comes from box or frozen altered with add-ins. For example, boxed mashed potatoes with herbs added, or, in this case, boxed cake mix with real butter and buttermilk.