1. Don't try to cover too much material. Don't tell readers everything you know in one article on how to pray or how to start a successful online business. About 1,200 words make a good how-to piece (although that varies with publishers), and today you don't want to write more than 2,000.
2. Start with a concept statement. When I start any project, I write the heart of the material in no more than 50 words. Here's my concept statement for an article on how to write how-to articles (even though I send it out in small pieces): Ten suggestions on how to write simple information to help others write how-to manuscripts. (I used 14 words.) Simple, right? If you can't put your concept into less than 50 words, you probably haven't narrowed your focus.
In 2004, I wrote a book called Committed But Flawed with the subtitle of Seeking Fresh Ways to Grow Spiritually. It's a how-to book, even though my publisher classified it as a devotional guide. Some church groups have used the book for adult Sunday school classes and one church is using it as a men's study.
Here's the concept statement I wrote for that book (with 36 words):
In his search for spiritual growth, Cecil Murphey studied the committed-but-flawed people in the Bible. Using them as patterns each day in prayer, Murphey envisions himself as the individuals who embody those spiritual qualities he desires.
Write a concept statement for yourself.
Be sure you know exactly what you want to teach.