I have searched and searched this site to find a definitive set of instructions on manually uploading new blocks. I've tried several search terms "manually upload blocks" "m,anual installation of blocks" etc and so on with no luck. Must be well hidden or described as something completely different.

Are there any instructions on how to do this?? I have no issues with FTP or anything, I just have no clue what folder to put my manually uploaded blocks into so that when I open dashboard and go to add functionality, they'll show up in the list of things I can install?