Command & Conquer: Red Alert 3: Uprising Hints, Tips, Tricks, Secrets, & Glitches

Commander's Challenge: Stack Buildings

In the Commander's Challenge map "Be quick or be dead" you start the match with all buildings of your chosen faction. To activate the glitch capture a war factory/armor facility/mecha bay from another faction than your own. As soon as the building is captured, build the MCV and deploy the construction yard. The game will automatically build all the buildings from the other faction on top of your own buildings.

All Your Academies Are Belong To Us

In Skirmish mode, if there is more than one Veteran Academy present on the map, go after them. Capturing three academies will have your forces automatically start at Heroic level, thus making them more lethal and automatically self-heal or self-repair.
A good map to do this on is Sub-Zero hour when playing with an ally. There are at least four academies on the map as well as hospitals, garages, and dry docks. Be careful though, your opponent (s) can grab some of their own academies, so take them out quickly to ensure your domination.
A good way to protect these structures is to set up an expansion base and subsequent defenses if applicable. In the case of the Empire, simply unpack some Defender VX and Wave-Force Tower defenses around them. Also be sure to keep these structures repaired.