Punctuation Full of Purpose

Chapter 15 was a nice review of the punctuation possibilities available to an aspiring writer. One thing I did learn from reading over the chapter was the comparative merits of dashes and parentheses, specifically when to use them for a desired effect. In my everyday writing, I usually use parentheses to expand on an idea, as an after-effect, and I only ever use dashes when writing up definitions. I learned that I can use the two interchangeably; the dash can be used to highlight explanatory materials, while parentheses are used to downplay those same materials. I now realize that every time I used parentheses in the past to expand on an idea, the use of dashes would have been more effective at conveying the importance of the additional information to the reader.
Oh well. You live and you learn. At least I now have a resource if I have any questions about punctuation in the future.