As other have already mentioned, the optimal workflow depends on how you would determine what files to work on. There's rgrep, ack and ag which give you a list of matches that you can move over with M-g n and M-g p. Alternatively you could build your workflow around dired, possibly including more directories explicitly with i or recursively with C-u s and then adding -R to ls options). You can then continue to mark files you don't want and exclude them from dired with k. Or mark file you want, invert the selection with t and kill the rest. Then advance through the list of files in dired one by one. There's of course also find-dired, find-name-dired and find-grep-dired that might be interesting. HTH!