Magic for the People!
Consider these three fictional worlds: Harry Potter, Star Wars and Avatar, the Last Airbender. In each of these worlds there is efficacious magic, wielded by a genetic elite; and in each of these worlds those elite magicians constantly bicker, and the common folk just have to take it.
I object! And I counter-propose that, in each of these worlds, the common folk shall scientifically investigate magic, deduce its nature and principles, and invent technologies to duplicate or surpass the powers of the magicians. Magic for the People!
Obviously most of the magicians would oppose this move; but a few renegade magicians would side with the common folk for reasons of their own. This creates conflict, which is always good for story-telling.
In the Harry Potter world, Hermoine is the logical candidate for scientific revolutionary. She knows both Muggle and Wizard worlds; she knows how science works; she sees how little the wizards know of their own magic; and she has no stake in the wizard-world power structure. When she does actual science on their magic, the wizards will feel disquiet, and rightly so; for as soon as Hermoine figures out how to give Muggles magic, then she’ll go on global TV.
Star Wars has already set the stage for the democratization of the Force; for it is now canon that Force powers depend upon having midichlorians. If it’s as simple and material as that, then let there be midichlorians for all! It’s a simple matter of medical technology. Of course neither Jedi nor Sith would take kindly to common folk doing Force tricks; only a real rebel would dare take on them both.
Avatar, the Last Airbender, also has openings to the democritization of magic. The Avatar can take bending away from people; perhaps he or she can give it to people.
In all of these stories there is the technical problem of what pseudo-scientific explanation to give for the magic. I recommend an elliptical approach; the viewers and reader don’t really want your pseudo-science, unless you can make it interesting. The trouble is that your lone imagination is no match for the marvels of the real universe; so perhaps your magic-science should simply be an imitation or parody of known physical law. Or you can imitate traditional magics; Voudon or some such; and there are modern analyses of traditional magics, such as the Law of Contagion and the Law of Similarity. What you should show is the scientific process; the questioning and errors and experiment and error-correction; as compared to the dogmatism of the magicians.
In all these stories the conflict is built in. Our heroes are sages, rebels and explorers, up against secrecy, ignorance and power.
No magical battles, please; we should establish early on that a machine gun beats a light saber.
In the end, the people win; perhaps in the form of a non-magician successfully winning a magical contest. Power to the People!