-Do not make your character an Alicorn. Choose 1. Unicorn, または Pegasus. And what's wrong with a good Earthpony?
-Do not make your character もっと見る powerful than the canon ponies. Example:My pegasus character is as fast/even faster than 虹 Dash and The Wonderbolts!!!!
-Try to make your character have a unique talent. Don't make it something that a canon ポニー already has. Example: My ポニー has Pinkie Pie's cutie mark cuz she likes to party too!!!!
-(I haven't seen this so far, and hope I never see it in the future) DO NOT MAKE YOUR CHARACTER THE 7TH ELEMENT OF HARMONY
-Do not have a innappropriate(excuse my spelling) character. あなた can have your character be mean, または even evil. But do not make them too violent for My Little Pony. Example: My ポニー is a killer and always carries 銃 to shoot ランダム ponies!!!!!!!!!
I hope あなた enjoyed my article, so have a nice 日 ^^