Since this is the first time we've done one of these things, I'm suggesting haiku to start, because it's short, easy, and most everyone knows how to do it.
However, in case anyone does not remember how haiku works, here's a quick primer. In English, it's simple: a line with five syllables, then a line of seven syllables, then a last line of five syllables. No other structure is necessary.
Here's an illustrative example of the form:
One two three four five
Two three four five through seven
Seven eight nine ten
...which has nothing to do with fanpop. You can do better, can't you?