One notable thing that Rowling really nailed is that witches cast spells. Duh. Spells are a directed and intentional manifestation of energy and serve a specific purpose. Just like Hermione knows what every aspect of every spell represents, so should a real witch who’s casting it. Every element of a magical working has specific properties and correspondences. Think: rose quartz, pink, and Friday to conjure love. Working within the parameters of what they want to do, a witch will pick a spell and its proper correspondences to make sure all energy is lined up and working toward the same purpose and goal. Just like Amortentia potion smells different to everyone, each spell feels and works differently for whoever is casting it.