Teacher Created Resources offers a series of books on three levels which includes a number of titles for working on grammar skills plus others that address broader language arts/writing skills. Some titles are repeated at more than one level. In such cases, the books follow the same outline, but present the material at a higher level of difficulty.
These "How to" books offer short lessons that can be used for focused instruction, but they do not provide the type of spiral coverage found in complete programs such as A Beka's. You might want to use the gentle introduction of these books for a student in the early grades, moving on to a more comprehensive course the next year.
These books are especially useful for breaking skills down into manageable chunks. Reproducible worksheets combine with discussion and fun activities to teach and reinforce concepts. Some activities are classroom oriented, but most can be used by homeschoolers, sometimes with slight adaptation. Multi-sensory activities help children with different learning styles master skills.
You can also purchase these books in sets. Titles at each level are:
Primary level (Grades 1-3): How to...Write a Paragraph, Capitalize, Punctuate, Write a Sentence, Use Parts of Speech, Write a Story, Write a Simple Report (quite challenging for most third graders!) , Make a Book Report.
Intermediate level (Grades 3-6): How to...Write a Sentence, Capitalize and Punctuate, Write a Paragraph, Give a Presentation, Make a Book Report, Write a Story, Write a Poem, Write a Research Report, Spell Homophones.
Challenging level (Grades 6-8): How to...Punctuate, Improve Your Vocabulary, Write a Paragraph, Use Parts of Speech, Make a Book Report, Write an Essay, Write a Research Report, Give a Presentation.
I would highlight three particular titles in the series: How to Write a Paragraph deals with basic skills that often do not get enough attention. How to Make a Book Report—at all three levels—offers a number of different approaches for relating the contents of a book as well as creative activities that spring from the book's contents (e.g., writing a letter as if you were a character from a book). How to Write a Story works on both organization and style while developing basic writing skills.