Hold your breath for as long as you can and write.  Only pen, no laptop or pencil.  You have to risk the mistakes with ink.  If you miswrite, cross it out and enjoy the lines used to indicate error.  And no laptop, no tech.  This must be an exercise of the natural, intrinsic reality.  Ink, no breath, then stop, breath.  Then repeat as much as you want.

So… To be clear…  All you do is hold your breath, and scribble.  When you need air, you breathe, stop writing.

 
Breath in, intently, slow, deeper than deep. 

Hold–

  Write–  let go…