JCS, from Irreal, recently highlighted fuco's dired-hacks. dired-subtree is super handy for drilling subdirectories down. Bound <tab> and <backtab> to toggle and cycle subtrees.
(use-package dired-subtree :ensure t
:after dired
:config
(bind-key "<tab>" #'dired-subtree-toggle dired-mode-map)
(bind-key "<backtab>" #'dired-subtree-cycle dired-mode-map))