When I think of a magical duel, I think of the Disney movie, THE SWORD IN THE STONE, where Merlin and Mim are taking turns throwing spells at each other and themselves. If one becomes an elephant, the other becomes a mouse which frightens the elephant, or they change the other into a mouse so they can become a cat.
Or the duel between the Death Eaters and the good wizards in HARRY POTTER AND THE ORDER OF THE PHOENIX where the wands are used almost as swords to parry and thrust spells and counter spells.
Or the final confrontation between the hero and heroine and the dark powers in Andre Norton's WITCHWORLD fantasy novels where the viewpoint character's emotions are more clear than what is actually happening from a magical perspective, and the fight is more about emotional strength than magical spells.
The trick in creating a magical duel without pushing it into a caricature of those I mention above is to personalize the duel. It's not the spells that are important, but the characters themselves. At the same time, you have to give better detail than the Norton novels' duels which often made me scratch my head and reread them several times before I figured out exactly what has happened.
If you keep true to your characters, their powers, and the unique world you have created, you should be able to avoid most of the cliches and create a duel worthy of your characters and your readers.