Last week when I was preparing for my webinar (and looking for cool tips and tricks), the following forum post was sent to me:

https://forums.autodesk.com/t5/post-your-tips-and-tutorials/drawing-special-symbols/td-p/5711899
In it, Kevin describes a way to leverage Unicode text and what he refers to as “AutoCAD-isms” to add special symbols and characters to your Fusion 360 drawings and annotations. Currently, this is more than 65k different characters ranging from alphabets, to technical symbols, to mathematical operators, and way more.

The following video shows how I was able to leverage this ability in a drawing I was working on recently:

Hope that helps!

-Aaron