The longer comics have mostly been sourced from story boards I sketched in surrealism ~2 years ago. Generally speaking, I will begin with sketching the characters in a seemingly random situation with no pretense and when ideas appear of what the single panel might be a part of, I indulge them and continue. In a way I understand this as opening a window into a world and progressively peeking through more and more.
I spoke about comic-surrealism here analognowhere.com/unix_surrealism/ , trying to dispel the idea that the output should be a pile of arbitrarily placed pixels. I use the characters as a medium or a tool for creating a surrealistic output. Ie: I know I will draw Girl and Fish, but not in what situation.
Most of the initial work is still done on paper. And most of it, like you suggest, never makes it into the world of Analog Nowhere.
For the more topical ideas, my mind is indeed not entirely free. Like the MATAVPS comic ( lemmy.sdf.org/post/14480541 ), but in that instance as opposed to the characters, I use the topic as my medium and let my hand construct the situation around it.