Trojan Horse

This strategy is well known, but I don't see it used too much. This strategy revolves around garrisoning units inside of other units, and then once the enemy is nearby, you ungarrison them all, and surprise the enemy. Below is the list of units that can be used for best results.

Mothership
Of course, you can't talk about the Trojan Horse without talking about the mothership. This thing can garrison nine space fighters, and heal them. So first thing you want to do is get a space link. You also need to get a plane house and research the first plane house upgrade, to get your plane capacity up to eleven. Then you need to get one mothership and nine space fighters. Then, you garrison the space fighters inside the mothership and decide what you can do with it. Its best to lure a weak enemy force to your mothership, and then ungarrison all the space fighters, and easily destroy the enemy force. However, you need to be careful with the mothership as if it dies with the space fighters in it, they all will die too.

Aircraft Carrier
The aircraft carrier works well for this too as it can hold planes. You will garrison a lot of planes in it, and when the enemy comes close, you ungarrison, and surprise the enemy. It works well if you have battleships around to protect the aircraft carrier.