Well, in a 'Naruto Different Dimension Fanfiction', a cool plot might be that Naruto is sent to a dimension where time moves at a different pace. He could age much faster or slower and has to deal with the consequences. Also, a dimension where the tailed beasts are the rulers and Naruto has to negotiate with them to return to his own world. Maybe a dimension where ninjutsu has completely different effects than what he's used to, like water ninjutsu being able to create solid structures instead of just water.
In this type of fanfiction, an interesting plot could involve Naruto entering a dimension that is a mirror image of his own world but with reversed moral values. For example, kindness is seen as a weakness and aggression is praised. Naruto would have to either adapt to this new world or try to change it. Another idea is a dimension where the Sharingan has completely different powers, and Naruto teams up with Sasuke to explore and understand these new powers in order to use them to their advantage and find a way back home.
One idea could be Naruto getting trapped in a dimension where chakra doesn't exist, and he has to learn new forms of power. Another could be a dimension where the Akatsuki are the heroes, and Naruto has to figure out how to co - exist or change that world. Or perhaps a dimension where all the dead characters are alive again, but in different roles, like Itachi as a rogue ninja fighting against Konoha.
One idea could be Naruto being transported to a dimension where chakra doesn't exist, but he discovers a new form of energy and has to learn to use it from scratch. This would force him to adapt his fighting style completely.
One idea could be Naruto traveling to a dimension where all the villains have become heroes. He has to adapt to this new world order and figure out how to get back to his own dimension.
One interesting plot could be Naruto traveling to a dimension where the Akatsuki are the heroes. It would be a complete role - reversal, and Naruto would have to figure out how to interact with them. Another could be a dimension where everyone has a different type of chakra, like water - based chakra for all shinobi, and Naruto has to adapt his skills.
Perhaps in this different dimension, female Naruto is a princess. But she still has her ninja spirit. She uses her skills in a different way, like using her agility to outwit court conspirators. And she might even start training the palace guards in her ninja ways secretly.
One idea could be that the main character accidentally activates a forbidden jutsu that transports them to different dimensions in the Naruto universe. For example, they might end up in a dimension where the Akatsuki has successfully captured all the tailed beasts and rule the world. They then have to find a way to team up with some of the remaining shinobi to reverse the situation.
One idea could be that Naruto travels to a dimension where all the female characters from different Naruto arcs are united. They all fall for his unique charm and his skills as a ninja. He has to balance his new relationships while also finding a way back to his own dimension.
One idea could be Naruto arriving in a dimension where chakra doesn't exist and he has to learn new powers. Another could be him meeting alternate versions of his friends in different dimensions, like a super - evil Sasuke in one dimension. Maybe he also discovers a dimension where the Akatsuki are the good guys and he has to figure out how to work with them.
A really exciting plot could involve Naruto getting trapped in a time - loop within the Juubi dimension. Every time he tries to find a way out, he ends up back at the starting point. He has to figure out how to break the loop by solving a mystery related to the Juubi's power. This would require him to interact with different versions of characters he knows, who may have different personalities and motives in this strange dimension.
One idea could be Naruto being trained by Kakashi's father, Sakumo. Since Sakumo was known for his skills, he could teach Naruto some unique jutsu and a different perspective on being a ninja. Another plot could involve Naruto being mentored by Tsunade's younger brother Nawaki. It would change Naruto's development as Nawaki might have his own special way of teaching. Maybe he'd focus more on medical ninjutsu combined with combat skills.
One idea could be Naruto arriving in a world full of magic. He has to learn to combine his chakra skills with magic to defeat a powerful dark lord. For example, he might use his shadow clone jutsu in creative ways within magical battles.