I used Emacs for several years before I discovered "project" (it's built in). If you're navigating dired trees or similar to find files or grep for strings in groups of files, this is like magic:
C-x p f (find any file in the current "project", e.g. git repo)
C-x p v (grep the whole project super fast)
It's embarrassing how long it took me to realize it was there all along. :-)
I am consistently using `m` for marking relevant files/directories in the dired mode and then `A` to find a regex among all included files. It does not seem that I miss anything by not relying on such a project approach.
C-x p f (find any file in the current "project", e.g. git repo)
C-x p v (grep the whole project super fast)
It's embarrassing how long it took me to realize it was there all along. :-)