To find a moment to just sit and write, no thinking, is rare, but everyone can do it if they try. No forethought should enter your mind. It is just about writing no matter the form or message, the flow is all that matters. If your mind flows you are a true writer.
Only submit work that is a stream of consciousness or a free write of some kind. Refined works are for somewhere else, unless it didn't start out as a refined work and we can see the original.