I Wrote That Book!
I have had the opportunity recently to work with K-1 teachers on helping children become excited writers from the beginning of their school career. What I have noticed, and I think research indicates this, is that 'writing' activities are too often tied to 'handwriting' activities. For some children, handwriting is very cumbersome at the beginning. Remember, early childhood children are still developing fine motor skills. If 'writing' activities (putting your thoughts on paper) are always tied to the need to handwrite, many children will have a negative view and misunderstanding of writing.
My suggestion is to keep those two subjects separate, at the beginning. Do handwriting activities and many other fine motor activities, to develop those muscles and skills. Then, beginning with pictures, allow children to explore putting their thoughts together through illustrations. If left to develop naturally, and with strong language arts instruction, a child will begin to add words and sentences to their pictures. This natural progression helps the child feel accomplished and successful. He also understand he can communicate through writing without the mastery of writing every letter perfectly.
Creating books during a writer's workshop is an excellent way to provide a child with open-ended opportunities to write and create. Check out the book by Ray & Cleaveland below. I consider it the best early writing book I've seen in many years.