If you want to learn to write, how do you do it? If you believe conventional wisdom you seek instruction, buy a book, read a magazine, or enroll in a course. Everybody has an answer, and is ready to help you learn to write dialog that pops off of the page, stories to rivet your readers, and screenplays that will have studios throwing money at you. Pretty much it's all designed to enrich those offering the instruction, and do relatively little to help the aspiring writer.
What you don't do is ask someone else to write your story, or screenplay, or poem for you. I've had several people ask me to write their stories for them. Unless its one of my partners and they're ready to start a new project, I never have. That doesn't count kids. My kids and I paint, write, or make-up and sing songs all of the time. Sometimes the kids will put on whole stage shows complete with choreographed dance numbers for a paying audience of six or seven (that depends on if we let them bring the goldfish.) Anything that allows them uninhibited creativity is a plus and should be encouraged, so that when they're adults, they aren't sitting around wondering if they need to take a course or read a book to create something worthwhile.
So what do you do? You write. You write all kinds of stuff. You write as if someone is out there to read what you're creating, whether there is or not. That's where blogs come in. Offer an opinion, create a story, do anything; to quote Nike, "Just do it." When you're done writing, read it, then tear it to pieces, and rewrite it. Whoever said writing is rewriting was only ninety-five percent correct. When you feel like it is the best you can write, post it and get some friends to read it and offer criticism, and if a stranger slams it, save the righteous indignation and try to see if what they are saying has any validity. I'm lucky enough to have a lot of what I write reviewed by professional editors, and I still have a little difficulty keeping that righteous indignation at bay.
Will this really work? Can writing regularly in a blog that no one reads improve your writing skills? Who knows? I'll get back to you in a few years, but in the meantime, I'll keep blogging, just for practice.