Winning space battles
In space battles as the Empire, put an Interdictor cruiser in the little box when organizing a fleet. By doing this you can send in your forces to a battle and stop enemy ships from escaping to hyperspace using only the Interdictor. When your opponent attacks the lone Interdictor, hyperspace in your reinforcements directly on top of them. Imperial Star Destroyers work best for this and provide a big surprise to an enemy player.
Zann Consortium
Always try to corrupt, enslave, build a black market, bribe, etc. any possible planets. This gives you sight on the planets base and units, in addition to many credits. This will also make the game much easier.
Winning space battles...