This can be as simple or as drawn out as you would like it. I use this activity to really get the creative juices rolling so I don't put to much emphasis on drafting and perfection. This assignment is perfect if you are having trouble motivating children to write.
First purchase a tabloid and go through it cutting out all the interesting (and age appropriate) headlines. For example, you should be left with quite a collection of MY MOTHER ATE MY BATHTUB! and OUR PLANE WAS HIJACKED BY ALIENS and 5 TON OCTOPUS MAN FOUND IN IGLOO articles.
Then the fun begins, throw out the actual stories and let your children create their own. They will have so much fun. We would pick our headlines on Monday, hand them in and correct them by Friday. At the end of the day Friday we would read the hilarious 'news article' out loud. It was a fun way to end the week and the kids look forward to the new headlines each Monday. You could even make your own Sci-Fi newsletter.