In automatic writing traditionally this is done by Spirit channelling through the medium who writes the message from Spirit for the reading purposes.
In my case I have done this and I find when I do reading for people I am sometimes as I speak or channel a message.
Spirit enable me to write the message as well and so this is another way I connect with Spirit. I do this in pictures and words very often in a Skype or face to face reading.
The other way is through email reading and I find this process is how I often channel the message from Spirit when writing an email reading, and again through pictures as well.