This is a fun question!
I find when things get complicated, I try to use different sentence patterns for the same concepts to help distinguish between different levels of nesting. And I tend to repeat small chunks to myself and then build up larger chunks. So in your examples, I might think:
(<|) : (a → b) → a → b
- okay, we’ve got a function
- the first argument is another function that converts
atob - the second argument is an
a - and it returns a
b
(|>) : a → (a → b) → b
- okay, we’ve got an
a - and we’ve got a function that converts
a's tob's - and it returns a
b
(I guess I like to hype myself up by starting with “okay” 
)
With those specific examples, I’m familiar enough with them that I wouldn’t normally think all that, but when I see functions that start to confuse me, that’s the type of self-talk I tend to fall back on.