I'd agree with almost everything Amidala said. I'd also add this:
Anti-fighter corvettes tend to target better when you let them do it themselves. Just keep them near your larger ships and leave them alone unless you're in trouble. They will target multiple targets at the same time. They'll quickly get rid of those pesky torpedo bombers and fighters, then you can tell them to focus on larger ships.
I usually go for the hangar bays first, to eliminate free reinforcements. (even before the shields) This applies to both Emperial cap ships and space stations.
If you're REALLY having trouble, you can always load the autosave which will bring you back to the start of the battle. That way you can experiment with different strategies in the same battle, however that could be considered a wimpy way to do it by some people.
If you have a space station, remember to buy any upgrades available, and don't forget that you can select the station itself and tell it to focus fire on a specific target.
Sometimes you can send ships into nebulas to hide them while their shields recharge.
One more thing: It's not always wise to use special abilities. For example, the Tartan's increase fire ability weakens the shield so much that it can cost you dearly. Pay attention to the side effects.