The writing bar is set low in the blog world, and among craft blogs there's a weird culture where nobody is ever supposed to criticize. That leaves a lot of bloggers wanting to grow in their writing and wanting to make the most of opportunities to write, but unaccustomed to criticism and unsure of how to get professional results. 
Writing a blog doesn't make you a writer; it makes you a blogger. Being a writer, whether journalist or "creative," means developing a broader and deeper set of skills, and truthfully, many years of dedicated education and practice.
This post isn't about that kind of writing. It's a set of tips that will help you write a better blog, or artist's statement, or short article for your quilt guild, or biography for your press kit. If you happen to be writing a book, it will even help you with that to some degree.
- Understand the difference between active and passive voice. Sometimes new writers will write in passive voice because they think it sounds more important or official. It doesn't. It drags down your writing. Choose the active voice. The difference? In active voice, you always know who is doing the verb, or the action. Examples:
Passive: The piece was quilted by hand with metallic thread.
Active: I quilted this piece by hand with metallic thread.
Passive: It was expected that this painting would be completed by November.
Active: The buyer expects me to finish this painting by November.
- Use correct punctuation and spelling. Not everyone agrees that it's important on the Internet, but I believe you should know and use correct punctuation. If you don't know the difference between it's and its, loose and lose, you're and your, or how to use a semi-colon, try to learn if you plan to be a self-edited blogger. You need to know the rules before you break them, and then break them with intention. The purpose of blogging is to communicate and connect, and bad punctuation and spelling inhibits that. Blogs are fast by nature and everybody makes mistakes and typos, but they should be the exception.
- Write like a grown-up. There's a kind of baby-talk that seems almost contagious in some art and craft blogs, even some that aim to be professional and serious. I'm not a fan, and I like to limit exclamation points and OMGs and LOLs. I understand that sometimes these are ironic or tongue-in-cheek, but if you're not sure if you're being ironic, avoid.
- But write simply. Big words and pretentious phrasing don't make you a better writer. That said, avoid saying that everything is "great." Words are wonderful, so try to expand your vocabulary.
- Write with authority. Instead of, "You maybe should think about trying gesso resist," say, "Try gesso resist." Instead of, "I suggest you consider sending your work to an agent," write "Send your work to an agent." All the qualifiers are unnecessary. They muddy up your writing and weaken your position. We know it's your blog, and therefore your suggestion; it's okay to be direct, and it makes for cleaner, more powerful writing.
- Don't imitate other bloggers. See above. Things travel fast in blogland, for better and worse; one person uses a phrase or style or writing tic and it goes viral, and then it quickly gets very, very tired and self-conscious. Avoid this.
- Know who you are and who your reader is. Many people do well by imagining one particular person that they're writing to. At least have a general idea of who you're writing for, their skill level, their age, their reason for coming to your site. Have a good idea of who you want to be writing for and why you're writing. Don't expect to please everyone.
- Read things other than blogs. If you want to be a good writer, be a voracious reader.
- My pet peeve: I'm turned off by diminutives like veggies and congrats. I realize many people are fine with these.
- My other pet peeve: Impact is not a verb. I don't care what your dictionary says.
- My other other pet peeve: Unless you're writing a blog about animals or children, a little information goes a long way. I once read a recommendation that a blog should be at least 80 percent on-topic; that sounds about right. A little bit of kids/pets in context is fine. If you want to post more than that about your darlings, say right up front that that's what your blog is about, or keep a separate blog for your family and friends.
- Finally, if your fabulous blog earns you interest from a magazine or book publisher, understand that writing a long-form article or a book for publication is universes away from writing a blog post. It's hard work. It goes on and on, with rewrites, corrections, instructions, and deadlines, and your writing will be edited, often heavily, by someone who has spent years writing diverse material, reading everything in sight, and learning to connect the dots and organize material in a logical and elegant way. They may have even written a few books themselves. Don't be angry or passive-aggressive. Appreciate what they do to make you look good.
- If you're planning to self-publish a book, you too need an editor and a proofreader, and possibly a technical editor.