Highlight a unit that will be created from the toolbar, then press A. Hold Z and press A after receiving the "Unit Ready" or "Construction Complete" message to build the same unit again without returning to the toolbar.

At the battle screen, hold L and press C-Up or C-Down to magnify and reduce the screen.

While playing as the Global Defense Initiative (GDI) on mission 6, gain access to the Air Attack. Then order your bombers to fly toward the lower left-hand corner of the screen and destroy a designated target. Follow the planes. As their bombs plummet to the ground, you should see a UFO hovering in the cleared area!