actually, i've also found the raid fleets to be extroidinarily useful. i especially prefer to use a raid fleet of one T4 and two Infiltrators on lightly defended planets and just go ahead and take them right out from underneath the Imperial's noses. its a bit difficult to do on the tougher difficulties or against a good opponent, but its definately rewarding.
another thing that i liked to do (with both sides) is to set traps. build two ion cannons/hypervelocity cannons on the surface and leave a lone frigate in orbit with just a Stage 2 Space Station. oh, and don't forget that the planet is situated so that a trade route connects to it which allows me to very, very quickly send in a massive backup fleet to help defend the planet before the other, and hopefully massive, fleet gets there. its definately one of the best tricks in the book. oh, and it works best if you have a gravity well of some kind already in orbit (via an Interdictor or the actual gravity well sattelite).
hehe, good times...
See the struggle of the faithless lot as they negate their time
How low to sink to the depths of their frame of mind