Relocated Items in macOS Catalina Explained - MacRumors
Handy explanation of the relocated items directory thing post upgrade to Catalina.
Set the hostname/computer name for macOS
I've had an issue with a Macbook Pro on one particular network where, even though I've set the computer name via system preferences, in the terminal (and via hostname) it's showing as the network-generated name.
This seems to help tidy things up.
Turn off macOS screenshot floating thumbnail
The floating thumbnail thing that's how macOS screenshots work now is really quite annoying. This tweet contains handy information on how to turn it off.
Switching back to Emacs causes the warning "recentf mode: Non-character input-event". · Issue #5554 · syl20bnr/spacemacs
While I don't use Spacemacs myself (this isn't actually a Spacemacs issue), I'm getting this a lot on my iMac and Macbook; especially when I've woken them from sleep.
How to record screencast videos with Mac OSX
Tutorial on recording screencast videos on a Mac.