Custom Keyboard Shortcuts you've made

What are some custom keyboard shortcuts you have made to make your system run smoother.

I still use a full keyboard so I programed the
F5 key to Check for Updates for any open app (not from the MAS)

It took a few shortcuts as some you need to spell it out verbatim

Example:
-All Applications
-Check for Update...
-Check for Updates...
-Check for updates...
-Check for Updates


I've also used F6 in Preview to open up the resize image feature.

In iTunes i use a ton of shortcuts to run some of my iTunes scripts as well.

I love the ability to make these custom keys within the MacOS.