I think this is a pretty classic setup, hence I'm hoping for a solution here.
In the finder, I have a folder "pictures" containing 15,000 pictures.
For each of these pictures, I'd like to send it to a sub-folder of the folder "categories". For instance, if there is a picture of a boat, I want to copy (not move) this picture to "categories/boat".
Currently I have two finder windows open, one with "pictures" and one with "categories" and I drag&drop every single picture one by one, while holding the Option key (to copy instead of moving).
Doing this with a mouse or trackpad becomes tedious very quickly and is slow and error-prone. I am open to any suggestions, even indirect ones leading to an identical outcome.
The absolute ideal would be that I could assign keys 0..9 to each destination folder, then I select a picture in the Finder, hit "5" and it goes to the destination folder assigned to 5. But I must be dreaming, right?