Attacking
Try to flank your opponents, as those areas usually are not defended as well. When launching an attack, place your troops to the extreme left or right side of the battlefield to avoid the defensive troops. Allow your own defenses to take care of the enemy forces that launch forward through the middle. Once killed, your troops will slowly regenerate health and can be redeployed. When fighting against an easy to defeat base, redeploy the troops as they are healed in the areas where they are most needed. When fighting a more difficult base, wait to get a large number of troops before redeploying them. This will mean that the opposing troops may get closer to your base while you wait, however launching a full health attack can cause more damage. The goal is to remove a turn from your opponents allowing you to take down some buildings. Repeat this until the largest threats of your opponent's base are removed, then deploy troops as soon as they are healed. Concentrate on eliminating the troop bunkers first because they will produce extra defenses. Afterwards, attack the enemy's defensive turrets and other troops. Begin attacking other players as soon as possible to gather resources. Search until you find a bases that have few defenses and lots of resources. Intentionally lose some battles as needed to keep your rating low, which allows easy to defeat players to remain within your searches.
Layout
Because enemy troops appear from predicable directions, you can plan a base layout that will be very effective. Create a row of walls at the front, and place a set of your most useless buildings (for example, resource producing buildings and worker stations) behind them. Next, place bunkers behind them, arranged centrally to cover the entire base with towers defending the sides. Have the front and middle area defended as much as possible.
Upgrades
Upgrade your buildings as soon as possible, in the following order: storage buildings, resource buildings (begin with Red Mercury Collectors), Army camps, defenses, then finally Command Center and Troop producing structures.
Various Tips and Tricks
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.