The following is a set of general rules and guidelines that will help you in the creation of original characters for the Naruto Universe. These are intended to prevent or reduce the instance of "Mary Sue" characters in the fandom by providing helpful tips at avoiding the common habits that give rise to them.
1. Know your canon.
If you are unfamiliar or just aren't certain about some of the series information (such as jutsu names, families, history, etc), look it up. Resist the urge to go running headfirst into creating a character without actually knowing what's going on. Do some research first. This prevents you from looking like an idiot when someone points out that your character is doing something that should be impossible in the Naruto Universe. Claiming ignorance is no excuse, when answers to your questions are no more than a five-second google search away.