Change default file type for screenshots.

defaults write com.apple.screencapture type jpg

Change frequency for app-store and OS update checks.

defaults write com.apple.SoftwareUpdate ScheduleFrequency -int 1

Prevent computer from sleeping for a specified number of seconds.

caffeinate -i -t 3600

For more options, use Option-click on the volume and network menubar icons. In general, try option click on anything and everywhere. e.g. use option-click on the notifications icon to snooze or un-snooze notifications.

Sources / See Also

5 Advanced Mac Tricks - Snazzy Labs (5 Advanced Mac Tricks You’ve Never Used - YouTube)