For those of you who don't know, OC stands for either Original Content or Original Character. It depends who you ask. I use it as Original Content because I have created non-character OCs. I created a town once. These are my personal rules. If you don't agree with them, you don't have to follow them. It's your character, not mine.
Warning: My grammar may be awful. I hope you can still read it.
Make sure to use the correct species: You may be aware that a lot of bronies hate Alicorn OCs. I personally don't have a problem with them if it works. One of the problems I have with OCs is the incorrect species.
Earth Pony: Strong, ability to grow