Static Defense, or SD, is easy to achieve in lesser degrees. But to be truly good at it you have to have one main focus. You have to be able to kill anything that can outrange 90% of your defense before it becomes a threat.
Early on find a choke point in which to build your defense. Build several T1 AA and Points Defense turrets on the very front edge of the defense line. As you progress up the Tiers add to the defense. By the end you will need at least 2 of every type of defensive weapon, and at least 2 fully upgraded shields. Here's an example of one such set up. Also, the numbers given are for a small defense. The more the better...
Point Defense [ T1=6 T2=6 T3=2 ]
Anti-Air [ T1=4 T2=2 T3=4 ]
Artillery [ T2=2 ]
The reason for the tactical missile launchers is that they have longer range than point defense and T2 artillery. The downsides though are they take up resources to build, much more than artillery, and you have to micromanage their launches.
Another major requirement is mobile defenders. Mobile defenders are key because they are usually more suited for combat and they are able to relocate between attacks, thus allowing one to save resources in the early parts of the game. Such units may be a group of T2 tanks, AA, and missile launchers.
Remember: the biggest key to SD is figuring out where you want your defense to be built at the very beginning. The sooner you figure out where your defense is going to be, the better.
Advanced Static Defense Edit
ASD or Advanced Static Defense requires a Tech 3 economy. The first part of ASD you should complete is Tech 3 anti-air covering your entire base. Then you want as many redundant shields as possible. Frontline defense positions should have three shields minimum. Make sure you also have Tech 2, and if you're UEF, Tech 3 Point defenses surrounding your base. Also make sure you have a few inside the base, for if the enemy does make it through initial defenses, then you have nothing otherwise.
Engineering stations are a good addition as they can repair your buildings automatically when they become damaged.
A good way to protect your shields from total failure in case of heavy attack is to build 3 Heavy Shields right next to each other. Then, if you have a really good economy, put normal (T2) shield generators right behind those. The normal shields will give the main shields some extra protection in case the main ones fall. This is important as shield generators have very low health and need protecting. A good way to keep shields operating is to make a T3 shield, and surround it with Engineering stations ordered to assist it, and those stations will help the generator recharge its shields drastically, often being able to withstand shot after shot from T3 artillery
Never under any circumstance should you put a power plant on the frontline. If a power plant dies then the buildings closest will fall easily from the explosion.
Experimentals and Defense Edit
Experimentals are powerful weapons, and if used properly they can deny your opponent victory. Certain experimentals are better for defense than others.
Aeon The Aeon's Paragon is the best for this as it allows you a near infinite number of shields. The CZAR is also usefull if the enemy comes in with heavy ground forces. The other two are useable for defense, they become far better if experimentals show up.
UEF The UEF have both the Fatboy and the Novax as major defense weapons. Both can do massive damage to the advancing enemy. The Mavor may be used in defense but is better employed shelling their base.
Cybran The Soul Ripper is amazing for defense as it can protect the base against anything. The Scathis is also usefull for defense. The Monkey Lord and the Megalith can be used effectively for either defense or attack.
Seraphim The Seraphim Experiementals are rather limited in defense. The Ythotha may used for defense but if it dies your base will take far more damage than if it wasn't there in the first place.
Static Defense Advance Edit
One way to use Static Defense offensively is to fully establish your base. Once that is complete, use engineers and mobile shields to slowly expand the defense forward. Use the old defense (Artillery buildings work well with this) to cover the new defense. As you creep forward continue to add shields to protect it. This is an expensive but effective way to hole enemies up in their base. Should the worst comes to worst your expanded defense will make it many times harder for opponents to get to your base.