JustFine, I have a graphic organizer to go along with "seed ideas" vs. "watermelon topics". If you would like it you can PM me.
I personally love teaching this in writing workshop!!! I actually draw a huge watermelon cut in half with seeds in it. Then I write the big topic next to the watermelon ("Going to grandma's). Then I draw lines from each seed to show the "seed ideas" or small moments from that day.
~Me & grandma made cookies
~ We stayed up all night watching movies
~ Grandma braided my hair
~ We got lost on the way to grandma's
You will be suprised but this visual really helps those struggling writers write small moments better. If a student ends up writing a "bed-to-bed" story, I confer with them and I coach them into deciding the most important event, or the seed story, from their piece and we circle it. Then I encourage the writer to now write a small moment story about that tiny seed idea. It works everytime!!!