Master Tactician Achievement
Earn 150 stars in Battle Academy challenges.
Battle Academy challenges are the single-player portion of this game. They present 60 battle challenges, where you can see what ships and weapons the enemy you will be fighting has. You then attempt to create the perfect counter fleet of your own to battle them, given a fixed number of resources, ship types, and weapons. The portion of your fleet remaining at the end of the battle determines how many stars you are awarded. You need to earn a total of 150 stars out of the 180 that are possible.
A great guide to earning the stars has been prepared by Zebrasqual, K4rn4age and NJDuke 007. You can find it HERE. For each level just construct exactly what is outlined in the guide. There is a small amount of randomness in every battle, so if you do not get the desired outcome the first try, keep trying a few more times.