When I start a new genre of writing I like to introduce it by preparing a PowerPoint that goes through all the steps of writing. For at least 2 weeks I would start my writing session with this presentation. Everyday we would start off our writing with this PowerPoint and we would concentrate on a different aspect each day i.e. Day Two...look at introductions (go over Present Tense) Day three...points in order. The PowerPoint would also be printed out so that children can refer to all of it at anytime. I like to have hyperlinked games incorporated into the presentation that can be played as part of the lesson, and children have access to these through a PowerPoint that is available on their computers .
I also design a framework that children can use on the computer or as a print out. Here is an example of one made in Kidspiration and here it is in Inspiration The more fluent the writer would depend how long they would spend on this framework. I would expect fluent writers to spend at least 2 to 3 days reworking and editing their writing.