Most writing books are pretty useless.
They are born out of a sort of academic incest, inbreeding. The authors look at what other authors got published and follow that. Publishers look at what other publishers sold and publish that. Jack Richards hints at this problem on his website. Shocking truth: Publishers are not in the business to help your students.
Publishers are in the business to sell books. If it sells but does not help they are not concerned.
But don’t teachers want to buy what will help their students? Teachers buy what seems popular and what seems like the other books.
Not only that, but publishers have to be mindful of the global audience, not your students in your school in your town in your country.
You are the only person who really knows your students and loves them and wants to help them and even some of you don’t care but are just marking time until 5 pm.
Do your own needs analysis. Find the exact kind of writing that your students will be expected to produce in real life, not just in school. It is very important to find realistic examples, not idealized perfect examples. This is the problem with nearly all of the IELTS books on writing. They use some expertly written samples of Band 9 writing when the students who are being taught can only hope for Band 5 or 6. If a guy wants to learn how to fly an airplane, don’t start him with a space shuttle. Find good samples of writing that you believe your students can achieve.
Now take the writing samples apart, reverse engineer them. What skills will your students need to produce that writing? How can you scaffold the students to achieve those skills?
Some of it is structural, the sections of the paper. This is relatively easy to teach.
Some of it is language. How can they learn that language? What is the language exactly? What is the vocabulary exactly? Believe it or not, most of that vocabulary is just higher level low-frequency vocabulary that you can find in a story about Lady Gaga or Yao Ming and it is more effective to let students study about their personal heroes or idols than some boring topic. Some of the vocabulary is scientific but you may not know or be able to teach for every specialized field of your students. Besides, that specialized vocabulary will be abundant in their textbooks so they will see it over and over.
So the best strategy is to teach the structure and help improve their general high-level low-frequency vocabulary through exposure to topics they find fascinating and exciting. Remember, students learn new language from input. If they need more new language they need more input like extensive reading.
Be sure to give the students assignments every week and score them to contribute towards their final score. Do not let them believe that they don’t really need to pay attention all year and can download and print out something the day before their final paper is due and pass the course that way. If students believe they can get away with that then all year they’ll never pay attention in your class.
These assignments have to be designed carefully otherwise you will be spending every waking minute correcting stuff or feeling overloaded and purposely not correcting. However assignments can be designed to target very specific skills and in this way it is much easier to manage.
Make sure that you are teaching something that they need to pay attention to.
How to do that?
Like I said, do your own needs analysis. Then you will know exactly what the student needs.