The best you can do to organise photos in the Finder for easy access is to structure your folders with nested subfolders. Don't put all your JPEGs into one single flat folder but create subfolders for related images in the JPEGs folder and name these subfolders in a way that allows you sort the folder in a useful way. For example, create a separate subfolder with photos of Bob, a separate subfolder for Jerry, separate sub folders for the parts of the ship, like Bow or Crew Mess. If you need the same photo in several subfolders, you could put an alias into the second folder.
To mark the important photos use the tags - the menu item "tag" in the File menu allows you to assign color labels. The photos inside a folder can be sorted by the tags as well.
For example, I am using a set of subfolders named by the camera I used to take the photos. That makes it easier to batch process the photos and tag the photos with metadata before I import them to Photos for Mac.