I always choose books that I like. I talk to them about what other authors say about writing. I let them know that I understand how hard they are working. When conferencing with a student, find something good to say about the written work. The positive statement could focus on the particular skill I am trying to reinforce, but it doesn't need to.
Students respond well to praise.
They need it. We all do. Know the students. I try not to become so focused on who I want my students to become as writers that I forget who they are now, which is just as important. Model writing in the presence of students.