Can you help me figure out an easy way to save things from my desktop to an outside source on a daily basis? (More info inside).

You could run a second cloud drive service.

For example:

1) Dropbox account for work
2) Box.com for personal items

On my Windows computer, I have four cloud drive services running; Dropbox, Box, Google Play Music Manager, and Google Drive.

Different stuff gets saved to different cloud drive folders.

P.S.
Is the goal a) keep things separate by whatever method? or b) avoid the cloud?

Download GFI Backup. It hasn’t been updated since 2012, but that’s OK, it works like a charm. I use it myself.

It’s basically a backup program. Choose the directories to back up (in your case, Desktop only).
Choose the target (a thumbdrive). You will need to remember to insert the thumbdrive before you leave for the night.

Schedule GFI Backup to run at (example) 8pm each night. It will create a backup of your desktop on the thumbdrive. Saved as a ZIP file.

You can have it save ALL forever, or you can have it save the last 3 (or 4, or 5, etc.) nightly backups.

Piece of cake. This is what I use. No cloud necessary.

My issue is being able to access stuff on my desktop in case something happens to my computer. Since I use a lot of charts that I change every day, I don’t want saving my desktop each day to be cumbersome.

Have you considered using a hardware RAID with an external drive? With a RAID, all your data is saved to two (or more) drives simultaneously and invisibly. If you use swappable drives, when one drive fails you simply swap out a new one and the RAID rebuilds itself from the data on the other drive. It’s how Google protects their data, for example. In your case, you’re worried about something catastrophic happening to your computer. If a tree falls on your house and it rains all over your computer room for days (that actually happened to someone I know) a RAID is not going to help if it takes out your whole system. So what I propose is this: get a RAID, then every night before you go to bed, swap out one of the drives and put it in a safe place, like inside a gun safe or something. Each time you swap it out, the RAID will rebuild itself, updating the data on the drive you’re swapping in. If anything ever happens to your computer, you’ll have an external drive backed up with your entire system on it. And because the RAID runs invisibly in the background, it takes no extra time or effort.

If you want to be extra-extra-safe, store one of the swappable hard drives in a safe deposit box or someone else’s house once a month or so, so that if your entire house burns down, you’ll have your data off-site.

Evernote.

I second @Blondesjon ‘s suggestion. I use Evernote. I also have company “cloud” servers that I place important materials (that are confidential and cannot go on Evernote).

My company has also placed “automatic” backup software and I can select which folders/drives I want automatically backed up on a daily basis. (Not using this at the moment..)

Lastly, just to be really redundant I use both an external hard-drive that can be plugged into any other computer and thumb drives.

I probably sound freaky cautious about backing up – and I have a Lenovo with a SSD hard-drive so technically I should never experience hard drive failure…but as a road warrior for work I am ultra-careful.
Never know when something is going to go wrong and I’m going to have to use someone else’s device, etc. (You don’t even want to know about my redundant packing of power and USB and portable power & WiFi devices. After a decade of this I’m so prepared my co-workers jokingly (but appreciatively) refer to me as the “Girl Scout”. Need a band-aid? Got it. Hem fell out? I have needle and thread and can fix it in a jiffy. Take your pick from Excedrin, Advil or Tylenol. You get the idea.