In most missions, skirmish and multiplayer mode you'll certainly need to build a base and it makes sense to build certain structures in certain places. Although some might consider this to be common sense it is still worth pointing out some basic points.

Make sure your Supply Center is as close to your Supply Dock as possible. The shorter the journey between the two points the quicker the money heading your way.

Always make sure that you protect your Supply Center heavily from enemy attack not forgetting to build anti-aircraft defenses especially if you are up against the US.

The US and China rely very much on power to keep their bases up and running so you must also take great care over your power producing structures.

When you build your power structures make sure you space them out. If they are too close together then it is an opportunity for the enemy to strike and shut down the power supply to your base and effectively shut down your base as an operation. A group of power structures would be a tempting target for a nuclear trike or Scud Storm.

The geography of your base should allow for your non unit producing structures to be placed towards the back. Structures such as the Black Market, Propaganda Centers and Supply Drops would fall into this category and deserve distance and protection from the front line.

The front of your base is where you should place the Barracks, War Factory or Arms Dealer. The reason is because this is where most of your units for defense will be produced and it makes sense that they have the shortest distance to travel to the front line.

As far as building your base is concerned the other fundamentals just centre on your actual base defences.

For the US this means placing Patriot Missile Systems in the key areas where you think the enemy is likely to attack from. They are effective against ground or air assaults and a group of three or four of them placed near each other will do a very good job.

The Chinese defences should be made up, side by side, with a Gatling Gun and a Bunker filled with Tank Hunters. Paired up like this they are a solid defence against vehicles, infantry and air units.

The GLA should build a comprehensive Tunnel Network so that defensive units can be moved around the base as quickly as possible. The tunnels themselves have a basic gun mounted on the entrance. In addition build lots of Stinger Sites to protect the base from air and ground units. Use them not just around the perimeter but also within the base.