Transnomino is a free Mac app that can automate things that would take ages by hand, and is one you need to know about if you regularly deal with large folders full of files. It has a bit of a learning curve but is extremely powerful, allowing you to rename a folder full of unorganized photos or music files. You just drag any folder or collection of files into the app, and then decide how you'd like to rename or organize your files. You can do things like find and replace terms, add a prefix or suffix, or number your files. You can also change the path for files, reorganizing them into different folders.
How to use Transnomino to organize your files will vary based on what you're trying to do. But as an example, I used Transnomino to organize my music files by dragging an album folder with files that weren't numbered: I choose the "Set" option, which allowed me to replace the current file name entirely, then I clicked the three dot button to the right of the Set Text field to add the track, artist, and title of the songs to the file name, adding the spacing and dashes between them myself until they looked right.
Instead of replacing the file names entirely, I could have used the "Prefix" option instead to add the track number to the start of the filename. If I had a bunch of albums in one folder, I could use the Path option to put songs from different tracks to different albums. The point is that you can spend a little bit of time setting up how you want to name your files instead of spending a lot of time manually renaming them.
There's also different metadata you can pull in depending on the kinds of files you're working with: If you're working with photos, the EXIF data is available, and there's even support for converting GPS coordinates to street addresses, meaning you could do things like organize photos depending on where they were taken.
The specifics will always vary depending on your needs, but the broad patterns is that you can use the metadata inside files to rename them. There's also support for things like wildcards and regular expressions, allowing you to run even more complex renaming schemes. Ultimately, Transnomino is an application you need to know about if you regularly deal with large folders full of files. It can quickly automate organizing them, which can make working with them a lot easier.
