Basic Base Set Up and Defense:
1. Your silos and Command Center are your most important assets. Place your silos around your command center.
2. Next, circle your silos and command center with all of your turrets. This will ensure when an enemy gets close to your resources they will come into the kill zone with over lapping fields of fire from multiple weapon systems.
3. The next circle is your resources; steel, coal, fuel and food. Have them wrap around the base in a circle surrounding your turrets.
4. Finally, the last protective circle is your barracks, armories, helipad, and body shops this will make the enemy slow down and have to kill these buildings to get through to your resources.
Some last things to leave you with:
1. UPGRADE YOUR TURRETS! I can't stress this enough. When I look to hit a higher-level player, I scout bases and look for low-level turrets. Remember: turrets can’t protect you if they are too weak. Start by leveling your gun turrets to 5 as quickly as you can, followed by the grenade (area splash damage), then plazma and finally the rail guns. I know upgrading rail guns is a pain due to time; but they are worth the trouble. Rail guns hit multiple enemies at the same time making them extremely valuable to your base defense.
2. Upgrade your resources, whenever you level or even when you are gone for a few hours they are maxed out giving you a bunch of free steel, coal, fuel and food.
~Wulfgar, Matheson Server