This is a fantastic tool for helping students to edit their own sentences. Teach students to draw each piece of the face after they have checked their sentence for that feature.
For beginning students, I stop at the finger spaces part and then gradually introduce the last three parts.
Teaching students to find the verb in their sentences is a really great way for them to see whether they have included ONE complete thought.
E.g. 'I went to the park it was fun' is a common type of mistake but it has 2 verbs- 'went' and 'was'. By identifying the verbs, they can see that they have two complete thoughts. They either need a full stop- 'I went to the park. It was fun.' or a conjunction- 'I went to the park AND it was fun.'
If students have remembered some finger spaces but not all, I get them to draw a straight line instead of a smile.