For a universe mashup, Star Wars and Naruto seem like an odd couple until you start digging into the parallels. They're both about chosen ones with immense power struggling against a dark legacy, right? Naruto Uzumaki and Anakin Skywalker share that 'destined for greatness but corrupted' blueprint, though Naruto resists the pull. I've seen fics where Naruto's chakra is reinterpreted as a manifestation of the Force, or where the Nine-Tails is basically a Force-nexus beast. The funniest part is imagining how different their fighting styles would clash—lightsaber duels versus ninjutsu hand signs. It forces authors to get creative with power scaling, which often ends up being the weakest link; some just make Naruto or Sasuke insanely overpowered to waltz through the Empire.
There's a tendency to drop Team 7 into the Galactic Civil War, which can be fun for the culture shock element. Kakashi trying to apply his ninja logic to spaceship battles, or Sakura being utterly bewildered by droids. But the ones that really work for me go deeper, weaving the mythologies together. I read one where the Sharingan was a bloodline trait connected to a forgotten Sith clan, and the Uchiha massacre was part of a purge by Jedi. That kind of lore integration feels more rewarding than just a crossover battle royale. The downside is these stories often get abandoned just when the world-building gets good, which is a constant hazard in our little corner of the internet.