Take your time with it, there's no rush. As the Mane Six told the CMC in The Cutie Mark Chronicles... "Think about what you're already good at." You figure out a talent you have, however big or small, tell it to us, (us being whoever else is part of the thread) and we'll think of a cutie mark. I'll get it drawn, colored in, scanned, and sent.
...Did I go into too much detail right there? Oh well.