Following up on this guest post I wanted to say that although grammar and spelling are of course important aspects of writing to master punctuation is—also—critical!

How you punctuate your sentences; whether you use commas or dashes or parentheses is so important, knowing when (to use a) comma or semicolon or “period” impacts the readability of “your” words.
When you’re revising make sure you’re using the right punctuation—does a dash or a comma or a parenthesis better fit grammatically. Does that semicolon really belong there or would the sentence read better split into two. Think about which punctuation mark gets your idea across in the clearest way possible…for the reader.
Punctuation also can change the meaning of your words?
I’ll say it again,
Punctuation also can change the meaning of your words!
(For a great lesson on proper punctuation usage, read Grammar Girl’s posts.)