Netrw can be used to great effect with no configuration. To navigate
directories mid-editing, use the below workflow from the Netrw help docs
(see :help netrw-i).
Bonus tip: In Netrw filetree view, use
gn to change root directory to the current selection.
vim .
(use i until a tree display shows)
navigate to a file
v (edit as desired in vertically split window)
ctrl-w h (to return to the netrw listing)
P (edit newly selected file in the previous window)
ctrl-w h (to return to the netrw listing)
P (edit newly selected file in the previous window)
...etc...