Branchless Programming: Why "If" is Sloowww... and what we can do about it! is an example of low level optimizations that you might pursue in a blockchain system to reduce the overhead of your runtime. But in the context of FRAME, a fair amount of the implementation details of much of the runtime logic is behind macros that may interfere with efforts to optimize, and worst case might even lead to worsening the operational overhead of of the logic you are trying to improve.
What best practices when you are trying to optimize are there in rumtime developement? What are the "footguns"?