My pro meeting audio tip for #GNOME users: map an unused top-right corner keyboard key as global shortcut for (un)muting the microphone, then paper-sticker-label it.
Now no need to have the meeting browser tab focused (or to remember each conferencing app's shortcuts) to toggle your microphone input.
The recording indicator in the top-right of your screen in GNOME reflects that change, although a bit too subtly. Up for grabs for newcomers: https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/8077
Screenshot of GNOME Shell's top-right system status icons, with the Muted state microphone icon (while an application is still accessing the microphone)
Screenshot of the GNOME Settings control center application's "Keyboard Shortcuts" dialog in the "Keyboard" panel, with my "Pause" key mapped to the "Microphone mute/unmute" action