• Study English
Ah, yes. We start with the ever popular study of the English language. You'll need it if you're planning to get anything published. Grammar is important if you want to communicate well or show an editor or an agent that you know what you're doing. Unfortunately, many manuscripts are unusable simply because they "ain't got no good grammar."
• Read all the time
You have full permission to immerse yourself in great picture books. Read as many as you can every day. Possibly the two biggest differences between a picture book and a short story is that a picture book needs a lot more visual potential and has a different type of rhythm. You'll develop a sense for picture book rhythm and plot that will serve you as a writer if you read many picture books.
You get extra points for this one if you set up a spread sheet, one slot per page number, and type in the text of a few of your favorite picture books. If you do, you'll begin to see a pattern which will help you in your own story development.
Double your extra points by reading Writing Picture Books by Ann Whitford Paul.
• Don't send your manuscript out before it's ready
Most writers have done this at least once. I did it more than once. (Ouch!) When you write something, of course it sounds right at first. After you leave it alone for a week and come back to it, it won't look quite so perfect. Sometimes I work on a picture book manuscript for two years before I feel it's ready to go out. During this time I rewrite and rewrite, in addition to getting feedback from other writers in critique groups.
• Know what a publisher publishes before you mail to them
Publishers don't just publish books. They publish specific kinds of books. Each one tries to fill a niche. Please, for the sake of those poor overworked editors and agents, find out what the publisher wants before you send your manuscript. Get a catalog and study it like our life depends on it. Do they only publish picture books with child protagonists? Do they have stories about animals? Do they publish self-help books for kids? Do they publish fiction or nonfiction? Find out. Make sure you are a fit so you don't waste your time and theirs.
Special tip I picked up from the 2010 Children's Writer's and Illustrator's Market: Do an advanced search on Amazon by typing in the publisher's name, age level of book, and dates so you can see what they've published in the past few years.
• Direct your muse
This takes the previous point one step further. I actually picked this up from a book on writing and selling cartoons. The idea behind it is for you to research a specific magazine or publisher before writing a story or book so you can fit into the niche they publish for. As writers, we're often encouraged to follow our heart, and there's nothing wrong with that, but a skilled, disciplined writer should be to direct his ability and fill a need.
The bottom line
Approximately 80 to 85 percent of the slush pile is not usable by a publisher. Probably less than 5 percent might even be something they would consider with more than a brief glance. If you want to be competitive, you have to be willing to do what it takes to get into the 5 percent that interests them. I know that nowadays even published writers have concerns about the industry, but publishing isn't going anywhere right now. There are authors out there selling their work. This means that when it comes right down to it, the only thing really standing between you and publication is you. And that's definitely an issue that you can do something about.