The syllabus is always the expected, best plan. Homeschooling is an imprecise art, and so the syllabi are flexible as we work through the year discovering areas needing extra time and ideas that are simply review.
The above image shows what a typical syllabus looks like for one of my classes. Each year I design a new syllabus based on the subject matter and emphasis of the class. I also pay attention to the make up of the class population. If there are a larger number of younger students or first-time-with-me students, my syllabus will be more concise. For high school classes, or classes merging history with writing, the syllabus is expanded in order to cover all the bases.