For me, AFAIR I read the nomicon pretty quickly, too, after the book. Then looking through the standard library (docs) to know the API for common types (especially the data structures) without having to look it up helps, as well looking through the reference for deepening the understanding of the Rust language in detail. Going further, reading (some of) the documentation of some popular crates helps as well. I’m personally not so much into creating my own practical code, hence I didn’t really ask any questions myself for learning Rust; so for me reading other people’s questions (and then the answers) or perhaps even trying to answer the myself in this forum also aided with learning Rust, I would say. I do write small test programs if I’m wondering what the compiler has to say about some things, so in a playing-around-with-the-compiler kind of fashion I do write code. Another thing is: There’s this “[src]” button on every function or type in std or any crate, so clicking that just reading the implementation of something that seems interesting but not too complicated is a great learning experience, too.
On certain aspects, especially the fundamental concepts behind Rust’s type-system, low-level stuff, types with constructors and destructors, etc. was in my case aided by knowing
C++ a bit and knowing Haskell really well; as well as some general knowledge from my computer science degrees.
And on some topics searching for specific tutorials / talks / etc. online helps, e.g. around