Reddit mentions of Style and Idea: Selected Writings, 60th Anniversary Edition

A lot has already been said that needed to be said, but I want to add that little bits of writing everyday goes a long way. Like training for a long race, building up your creative stamina bit by bit will give you a lot of ability when sitting down to write.

There aren't a whole lot of inspiring books on composition, but reading books by composers (ex Schoenberg, Hindemeth, Messaien, etc...) will give you an interesting insight into their creative process. I'd also recommend The Muse that Sings which is a nice collection of interviews from major living composers who talk about their processes as well.

Other than that, learn theory/form, analyze a lot of music that you like, and learn instrumentation. The rest will be up to you.

i suggest you read this if you want to learn about serialism

also, reading Schönberg's essays will show you the artistic intent

read about expressionism as an artistic movement to understand its aesthetic goals

i personally can't improvise a fugue, does that make it noise? difficulty of a style doesn't make it noise, it makes it challenging, not all of us like living life in easy mode