By brolloh We can’t believe it’s taken us seventy four tips to get to this one!
This tip has a big fan base amongst educators but we’re sure you’ll find a valuable use for it.
OS X has a universal zoom function to get you closer to your work. To enable this, head to System Preferences > Universal Access > Seeing, or the SquareCMD endorsed method: alt + cmd + 8 for On or Off.

After this is enabled, simply hold ctrl and scroll up on your mouse or trackpad. If you have an older Macbook or a non-scroll mouse, hold alt + cmd and press + to zoom in and – to zoom out
As you can see here, zoom has a wealth of uses.

More soon!

Source: SquareCMD