The first attacks start right after your shield runs out, so make sure you've built as many different defensive towers available to you as you can.

Use all three days at the begining to your advantage to max out your defenses.

As soon as you can build a War Factory and you will be able to start training heavy machinery.

When your Command Center reaches level 4 you will be able to build an Aircraft Factory as well.

As in most games of this type diversify your troops in order to make it easier to win battles against other players and against the Lone Star Republic.

Attacking friends, added via FaceBook, is one of the most lucrative parts in this game. You can earn much this way.