I teach year one and year two Middle School English. There are text books for both years. There are is also a companion book for teachers and students, which, being in Korean, I only consult to study Korean.
I use these books a lot. I am expected to include material outside the scope of the textbooks and would do so exclusively except for the fact that I am usually exhausted of teaching ideas. Even using the text books I am often short of approaches or ideas.
In general I find the books too difficult for average students and the lessons move too fast. Korean students are told to memorize lessons. So, I design lessons to help them remember the new material by using the new words or sentences in a variety of different ways.