Hello, hello, could you please say more about how you use Microsoft OneNote in your professional life? I need all the help I can get to stay organized & on top of things, so I would love to know.
Sure! I use it less than previous because there's less randomized stuff I need to do now, so I don't need such robust management, but I can talk about how my use began/evolved. I started using OneNote because it was less finicky than Word but still had an autosave function and basic formatting, so it was useful for initial drafts of documents, taking notes on meetings, and keeping track of information I needed at my fingertips frequently.
OneNote's largest "unit" is the Notebook. You can have multiple Notebooks but I've never bothered; still I can see how if your screen was public a lot, you'd want to put some things in a separate Notebook. The Notebook then breaks down into Sections which look like tabs, which I would assign to broad things like "Meeting Notes", "Assignments", "Templates", "Personal" and "Excel Hacks". Sections break down further into "Pages"; each page is a document stuck into place, which you can title so that you can have a list of "pages" on the sidebar and find the one you want easily. Text in Pages can be formatted to some degree, and if you copypaste from websites, it'll tag on the URL of the site you pasted from, although you can also turn that off if you want. You can drag and drop Pages from one Section to another pretty easily.
So, for example, I'd have a "Meeting Notes" Section, and when I clicked the tab for that section I'd have a list of Pages, each of which was notes from a meeting I'd attended. Every time I went into a meeting I just made a new page, gave it a meeting title and date, and took notes on the meeting into the page window. The "Meeting Notes" Section thus became a fully searchable record of meetings I'd attended and what was said. When meeting notes were no longer relevant I'd drag them to an archival Section to retire in peace.
Here's an example of my Excel section:
You can see "My Notebook" up in the left top corner, my current Sections as tabs at the top, and the pages list on the left (I think more modern OneNote skins put the pages on the right, I moved mine back). Each line on the left is a separate "page" that tells me how to do something in Excel, something I need to do a lot but can't commit to memory (or couldn't but now have, it's a trifle out of date). So we're in My Notebook, section Excel, page Formatting Stripes, and on the right you can see how to format an Excel sheet so that it has alternating colored rows (there are other ways to do this but this way the stripes always stay alternating no matter what moves where). In theory I could dump all this stuff into one Page and call it "Excel" and put it somewhere else, but I liked having an easily-visible list so I don't have to scroll a single document to find what I want.
There aren't nearly as many tab/sections as there used to be; "Assignments" covers "all work that is not excel formulas" and includes stuff like instructions for how to pull a query in our database, a list of what everyone does at our company, a yearly guide to our events program, a few other things. I don't have a "Personal" section any more but I do have 2-3 pages in the Assignments section that are personal notes.
There's no inbuilt tagging function but because the entire notebook is searchable, if you're really into tagging you can simply add keywords to the top or bottom of a page.
I have OneNote pinned to my taskbar in Windows, and it's basically always open but it autosaves, so adding stuff is super simple; if I find a bug in our database or a quirk I want to remember I just click over to OneNote and add it to the database file, or similar.
I don't use it on my phone or tablet, because if I'm at work I have access to my laptop generally, but OneNote does sync across devices as long as you're logged in, so if you have OneNote and a Microsoft login you should be able to access it in multiple places.