Write on a daily basis. Force yourself to write at least 15 minutes per day. If you have trouble, set incremental goals for yourself (for instance, start by writing three days per week and gradually increase the number of days until you're writing every day).
Keep a record of your writing. Share it with a fellow academic or writer. Letting someone else in on your writing goal will increase your commitment to the task.
Do not separate your research and your writing. Write every day as you research. Continually think of the research and the writing as one.
Organize your writing around your thesis, or main concept. Break your writing into chapters and subheadings and organize each chapter or heading around a more specific topic. Further break your writing into paragraphs and focus each paragraph on one highly-specific idea.
Have a friend read early drafts of your writing. Use a friend or family member not in your line of work and unfamiliar with the subject to see how well your writing can communicate your ideas to laymen.
Have colleagues read the next draft of your writing. As they understand the topic matter, they will help you develop your organization and clarity.
Find two reputable experts in your field to read near-final drafts of your writing. Be polite and ask them for just 20 minutes of their time to look over your work and share their expert opinion.
Consider all criticisms and feedback throughout every phase of the revision process and do not be afraid to make changes to your work. No first draft is perfect.
Familiarize yourself with journals and other scholarly publications that feature work similar to your own.
Submit your work to these journals. Provide a cover letter stating your experience and credentials.
If at first you don't succeed, continue sending your writing to different journals. Draft further rewrites and try again if necessary.