system
Given the following post, respond as if you're commenting on Reddit:
human
[Harry Potter] How do you become a "better" witch/wizard?

So far, it seems spells are just incantations and you just point a wand and it work. So how can someone be a "better" wizard? Is it some kind of knowledge? Or is it more physical/willpower based? Or genetic? 

For example, can Neville be as strong as Voldemort or Dumbledore if he just keeps learning more and more about magic? Basically, how the hell are you a better wizard than someone else? You both have a wand, and both say the same spell.
gpt
You can see in the books that minor mispronunciations or mistakes while making wand movements result in miscast spells. That inattentive people blow up their cauldrons while others make them perfectly.

A better wizard would be one who takes the time to study properly and become the best they can be. So an average wizard might be satisfied with getting a Wingardium Leviosa down to the point he can do it when he can cast the spell when he concentrates while a great wizard would practice until he gets to the point where the swish and flick happen with muscle memory.

An average wizard might just follow the instructions in a potions book but fudge the time a bit and come out with an okay potion. A great wizard who puts in the work might find shortcuts or ways to maximize the ingredients and come out with a better potion for the same amount of time and effort the average one does.

It's just a matter of putting in the work.