"when you are on the cloud city mission with the galatic empire, take at least 2 transport ships and all your bombers and a couple of fighters and head south, there you will find a small airbase.By the way do not use the transport with your workers on it.or your screwed.

Anyway,use the bombers to destroy all of the air towers to allow your fighters to have troops to have air-support,there, you can build your base and use the it as a launchpad to launch your own invasion on the rebels and win the level." - freak_90

"If you and your enemy are seperated by a forest you can launch a surprise attack against them with the help of an air cruiser. Just set the Air Cruiser to attack the ground and then create a path through the woods from your base to theirs. Often times bases having a clearing behind them that is unguarded because people assume they wont be attacked from that side. Make the path lead there and then march your troops through your enemy's backdoor. Try making a distraction first by having some troops attack from the front. They'll never see it coming." - paul