I've enabled Auto-backup in the new Google Photos app. And I have excluded some folders from being backed-up. But this seems to be all or nothing. I want some of the photos in those excluded folders to be backed up. Any way to do that?
I've been trying to do what you're asking for a while and I think I've found a way. Upload the pic to Google Drive and go into pic info. From there click 'send to' and select 'upload to photos'. The pic/pics you uploaded should be in the 'photos' section of Google Photos. After that you can delete it from Drive. Hope this helps