If you are playing the Dread Lords campaign in Ultimate edition, then here is a tip:
Focus on smaller ships in large numbers. They each should have lots of firepower (missiles will help you out) and they should be in groups of 5 or more (a bigger logistics will help you on that).
Larger ships are more useful on defense, especially combined with Omega Defense System super project.
Also, have each planet keep a "interceptor ship" to stop transports if you can afford it.
If you need more tips, then you could ask around.