In one of my first TILs ever, Head Of File Name, I wrote about a fancy, archaic way of popping open a netrw view for the directory of the current file. To this day, I still use it all the time when I'm curious about the other files co-located with the file I'm editing.
There are a couple other ways to do this that arguably require less finger gymnastics.
:Explore
This has the same behavior :e %:h at the cost of a few extra (easier to
reach) keys.
There is also
:Sex
which opens it up in a split. And as you'd expect, you can also use :Vex
for a vertical split.