Neil Gaiman, On Procrastination:
3) Step away from the Internet. Turn it off, or go somewhere it doesn’t exist, or write with paper and a pen, or do whatever you need to to place yourself in a world in which YOU ARE ALLOWED TO WRITE OR NOT DO ANYTHING AT ALL, JUST STARE OUT OF THE WINDOW. But you can’t do anything that isn’t writing or not doing anything.
Staring out of the window gets boring after a while, and it is more interesting to write.