This is an 8 1/2 by 11 poster that I made to show the 5 things you need for a good sentence. I used it with low second graders, and learned the concept from a first grade teaching team.
I went through all the "star points" with them, then we did some examples of good star sentences versus sentences we needed to fix. Then they tried their own and I went through the star checklist with them. After only two days, the students started to check their own sentences against the poster!