Start Global Edit
Adobe Illustrator CC 2019 includes an amazing new feature that allows you to select, then edit multiple ‘similar’ objects at once.
First, select an object or group, then go to Select > Start Global Edit (or click the button in the new Properties panel), and other objects that have similar attributes become selected. Any changes to that first object are immediately applied to the others.
This concept can be approached in other ways, but this is so fast and easy!
[forgive the bad audio towards the end of this clip… and the blooper]