MC is Reborn in the Jiraya/Tsunade era.
You can either make the MC an Orphan or you could give him a family. ( You can either make the MC be Reborn as a baby or make him take over someone else body.)
I think it would be cool if he was apart of a clan other than the Uchiha or Hyuga, so Uzumaki, Sarutobi, Yamanaka or Hatake clans would be perfect.
Write about his time at the academy and his relationship with the three sannin. (I think it would be cool if the MC didn't know everything about the NarutoVerse so he wouldn't just kill Orochimaru straight away.)
You could make the MC and Tsunade into lovers.
Make the MC a prodigy never seen before and make him set different records like yougest graduate from the academy or something along the lines (You want to make it so everyone knows who the MC is because of what i want to happen during the later parts of his life.)
Write about the 2nd Shinobi war and make the MC feared in other nations. ( MC would be around 26-30 years old during the 2nd war.)
After the war ends you could make the MC become Hokage or not depends on your choice, just give him a really good reputation.
Write about the 3rd shinobi war and make him die during it (You can make it that Kiri, Iwa and Kumo decided to ambush the MC because he is too much of a threat so they decided to send their best shinobi to kill the MC) Make him take out like 90% of the army that ambushed him to make his reputation even greater.
You can continue the story by making Kabuto use the reanimation Jutsu to bring back our MC to life. Obviously because of the MCs reputation it would have a big impact on the war.
Make the MC get out of the reanimation jutsu and take control of his body to help fight against Madara and Obito.