Scaling your sequence so you can see the entire project is useful. Doing it quicker is even better.
For Final Cut Pro users, click on the sequence and hit Shift+Z. This will scale it perfectly. This command also works in the viewer window to zoom your video/photo/music file back to the “fitting size” for that specific window. It’s useful when you accidentally zoom into the picture you had in your viewer when you meant to zoom on to your sequence.
For the Avid user, use Command(Mac)/Control (PC) + / on the keyboard and it will do the same thing.