Can anyone explain how to use iCloud to free room on my Mac? Really, not the basics.

What users want iCloud to be and what it is are not the same thing.

That is certainly true. Unfortunate that Apple promotes it as exactly that type of a service: Manage storage room on you devices using iCloud...

Feedback for Apple goes here >>> http://www.apple.com/feedback/

That was actually helpful. Thanks for the link.

For others that are as confused about what iCloud can and cannot do to help create space on your Mac, hopefully the previous responses will help you sort out what to do. And if you are as disappointed as I am in how iCloud actually works, the feedback link provided above is the place to let Apple know how cool iCloud could be.

My resolution, in case it helps anyone: I moved my 51GB Music folder contents, and my iTunes Library to a Network Attached Storage (NAS) device, ensured that all the files copies correctly, trained iTunes where to look for the files now they are moved, then deleted the files from my MBP. This gives me a while longer to work with this MBP before it fills again and I have to delete something else off it that I don't want to... I am *really* hoping that my Mac doesn't now see all that free hard drive space and decide to "optimize" my storage by downloading local copies from iCloud storage until it fills again... we shall see.

Oh yeah, and cancelling my $10/mo 2TB iCloud drive, and certainly not now upgrading to the Apple Rundle as it no longer makes financial sense. Alas.

I get it, but this is both frustrating and concerning. It's clear that iCloud was originally designed as a "sync" service to keep files available across mac ecosystem devices. But like many early use cases it has morphed to provide cloud vs local storage. Unfortunately, it seems like this use-case isn't really sufficiently developed yet:

1. It works randomly, with very limited user-control over what files/folders to move to store on iCloud (I mean sure, I could store all my files on the Desktop or in the Documents folders, but that defeats the purpose of having dedicated system folders like Music, Pictures, etc...)
2. By "works randomly" I mean that it's clear that some files and folders within the Desktop and Documents folders are uploaded to iCloud and many don't, for whatever reason (the black box syndrome... the logic for how this is supposed to work should be transparent so users can manage accordingly)
3. Using iCloud corrupts all local TimeMachine backups?!? So all my local backups are missing any files that are in iCloud? Wow, that is terrible (and I guarantee 99% of Mac users don't know that the files they think are on their attached drives are missing anything they ever synced with iCloud that aren't also stored locally)... just wow.
4. Apparently, in newer versions of MacOS, you can manually tell iCloud to "Remove Download" (right click on the file in iCloud folder)... But it is completely manual, as in, you have to individually select each file. In 30 minutes I was able to remove .12GB of files on my MBP, so I should be able to get a couple gigs of free space in, I don't know a week or so of right-click, remove download? You can apply remove download to a folder... unless there is a single file within the folder that is already in iCloud, in which case you have to open the folder and select all files that aren't already there... Bonus annoyance: For some unknown reason, Remove Downloads doesn't work on all files... you select the file, hit remove downloads, the file shows the little cloud icon... and then it goes away and the file is still local.
5. What the heck does "Optimize Storage" even mean? If you check it, it keeps local files that it thinks you use regularly, if you uncheck it, it removes them? Or is it the other way around? Or what the AF? I've read the documentation several times and it is clear as mud. In any case it doesn't seem to work on my machine... just got down to less than 7MB of available storage on my local machine, which means the MBP goes into survival mode until I delete a bunch of files I'd rather not delete. This is sub-optimal.
6. If Apple really wants to extend the power of iCloud beyond file syncing across devices to include cloud-based storage of rarely used files to keep storage headroom on iCloud enabled devices, then it really needs to work like a cloud connected backup drive. This means that (preferably all user controlled) users need to be able to know which files will be in iCloud vs local, and most importantly, Time Machine needs to work on both the local and iCloud connected drives so that ALL files are version-controlled and backed up safely, ready to restore any of the connected devices that might fail for whatever reason.

Given all that, I really can't see the point in continuing to pay$10/mo for 2 TB of iCloud storage... much better to buy multiple, raid-array, redundant local hard drives for Time Machine backups, and store some off-site... exactly the opposite of why cloud storage and backup is so valuable. Or use DropBox or something... Alas.

Thanks -- have read and followed all those directions already.

What I think is going on is that my Mac is not "Opimizing" correctly. I believe I have all the correct settings, but my MBP got down to less than 7MB of storage space, at which point it becomes unworkable... can't save, can't check mail, can't... well you get it. I don't know if there is a setting somewhere that says something like, "Never let my MBP get below 1GB of storage space" or something, but clearly, letting the hard drive fill to the point that the laptop no longer works as intended is not acceptable.

Mid-2012 Retina MBP, 750GB HD