Carry a pad around with you. This way, you always have a sheet handy to write down your thoughts. If you are intimidated by a blank page, scribble on it. If a blinking cursor on a blank screen is psyching you out, type anything. Just start moving your fingers.
Writing is one of life's great pleasures.
Most people don't know that because they never had the courage to do it. But anyone can write. Or get out your date book and schedule a time to start. Workshop Inc. Gotham Writers' Workshop is a registered trademark.