How to disconnect two iPhones from each other?

Me and my brother have iPhones, and when ever I download an app or make a contact, it goes to my brothers phone. How do I stop this?

Settings -> iCloud. Disable everything.
Or you can just delete the account and never worry about it again. That's 2 ways take your pick. Oh to delete the account won't do anything to your apple ID account but to do this you go to "Settings" --> "iCloud" scroll all the way down and press delete account