One way that we practice writing is by taking turns adding sentences to a story. Here is one that the elementary students wrote recently.
In case you can't read it, here's what it says:
Once upon a time, there lived a big dragon. The dragon captured a princess. The dragon took the princess to a mountain. The mountain was so high. The princess looked down from the mountain. In the mountain, there was a jail. The princess put the dragon in jail. But the dragon ate the princess. An ogre killed the dragon and took the princess out. The ogre made the princess a slave. The ogre died. The princess went back to the jail. In the jail was a boy. The princess helped the boy get out of jail because the princess wanted to marry the boy. The boy saind, "Yes!" and they lived happily ever after. The end.
I like the struggle between the students who were cheering for the dragon and ogre, and the students who wanted a more typical fairy tale.