I love your point about your music being a 'reaction to' or 'building upon' what's gone before. A true artist is always building upon an existing legacy, even if they are 'reacting against' music that they hate.

I go through phases of absorbing lots of media. Listening to music, reading books etc.
But then I tend to go through another phase where I am not wanting any sensory input. I am very tuned in to an inner voice that is leading me to express what needs to be expressed. There was a period of about 3 months last year where I was productive in producing psychedelic trance music, In between I would go on long bush walks and listen to classical around the house as background music. Not much else.

I have been playing fingerstyle guitar for a long time whilst doing no study or listening to other guitarists. I believe discovering the instrument itself has been inspiration itself but now I am starting to enter a period where I am craving to use my left brain a bit more, apply some 'proper' theory.

There are times where the relationship between 'absorbing' and 'producing' seems a lot closer in time. For instance on a trip to the country I got really into the Steve Earl song 'Copperhead Rd', so much so that I used it a very similar format for a song I wrote about my feeling about moving to the country.

I would say in addition to absorbing more art, absorb more experience. New places, people, emotional experiences can all be catalysts for that creative 'reaction' to take place (perhaps why breakups seem to often trigger creative output). I'll be writing a post about art as a reaction to geography as soon as I finish this reply if you are interested.