Here is a stream of consciousness exercise I like to do if my brain gets jammed and I suffer from terminal writer's block.  For me, I write in bursts.  Sometimes I feel invincible, like my next book will break new ground and be beloved by millions (I have an active imagination), which gives me the fuel to write for hours.  On the other hand, sometimes I have zero motivation and find that I surf youtube for hours and write maybe a sentence of my story. Then, when the day is over, I feel like I've failed, for not being able to push myself to write even one page.  While you cannot dictate the creative process, you can refine it with some discipline.  This stream of consciousness method can work.

Describe a room in your house and write about it for 25 minutes straight, without stopping.  Forget about form, forget about plot, forget about spelling and grammar!  Picture yourself setting your work ablaze (or just plain deleting it).   Discipline is built bit by bit.  This is something I learned in Korea.  If you do this regularly, you'll find yourself able to write longer and with more quality, rather than spending your afternoon checking the baseball game score.