Best way to learn optimizing?

Rust has became one (if not) the best low level programming languages, it attracted a lot of new programmers who are interested in rust unique concepts and I am one of those :).

I always wondered about the best way to optimize some stuff (such as reading structs as fast as possible, why vectors could be sometimes a bad choice. Etc.)

Is there a guide/challanges/documentation on how to make a code more faster?