A well of inspiration: Sketchbooks

For me, inspiration can come from many different places, for example nature, experiments, photos, books, poems, exhibitions, prayer/meditation, podcasts and documentaries. I tend to scribble ideas and quotes on the back of an envelope or scrap paper and cut out inspiring or intriguing images from magazines and catalogues. In addition, I often keep past work as potential collage material and starting point for further work.
Over the years I have tried various ways of collating and curating the avalanche of information and ideas I am collecting: A4 folders, clear plastic boxes, shoeboxes, an electronic filing system, journals, sketchbooks... I have not (yet?) found a way of processing everything in one place, but sketchbooks have become an important part of the journey.
I confess that I have had a love hate relationship with sketchbooks in the past. I used to have a fixed idea of what a sketchbook "should" look like. I assumed that the only valid sketchbook was one where I recorded my observations of the external world as accurately as possible.
Working on my sketchbook felt like a chore rather than a joy. Observational drawing can be a helpful mindfulness exercise, but if I want an accurate representation of something I generally prefer the immediacy of photography. I am interested in trees, the moon, mountains, paths and butterflies as symbols and metaphors for life's journey. I want to explore soulscapes rather than landscapes. My artwork is usually intuitive and experimental. I may work on paintings on and off for several months or even years.
There was a disconnect between my sketchbook and painting practice. ( I have just read that there are two broad classes of sketchbooks, those that record an artist's "documentation of the external world" and those that "follows the artists' digressions and internal journeys as they develop compositional ideas." I wish I had been aware of this distinction years ago!
In recent years I have allowed my sketchbook to reflect my divergent way of thinking and working. I now use my sketchbooks to play and experiment, visiting and revisiting materials and themes.
I am currently finishing a sketchbook with almost 100 pages (although I am not sure that the sketchbook will ever be truly finished - I have already added further elements to some pages as I have thumbed through the sketchbook.) I am planning to share pages from this sketchbook in coming weeks.
In the meantime, I am wondering how you process information and ideas...