Time Machine directory exclusion
This very simple but useful tip. I usually don't backup my "/Documents/Microsoft User Data" or "/Documents/Virtual Machines" folder. But uses Timemachine.
From the Terminal to set Timemachine
sudo defaults write /Library/Preferences/com.apple.TimeMachine \ SkipPaths -array-add “PATH-ONE” “PATH-TWO”
From the GUI
Open System Preferences > Time Machine > Options.
Time Machine Exclusion