Tips:

This will briefly tell you how to efficiently manage your army during any skirmish game. Again, this is really long, but I got away with it the first time so it should work. Site: Please post this hint! Noobs to the game as well as many rookies will thank you. Anyway, this is a sort of tie-in to my first series of hints, telling you what to do once you follow the first few steps of my first hint.

Supplies: (US strategy) For each Supply Source you control, you should have 2 chinooks gathering supplies. This is important with the US--because everything they have is so expensive, a 3rd Chinook is a waste of money and it will slow the supply gathering process up because the other two will wait for it to finish gathering instead of gathering like they should be. However, this has one exception. If the supply source you control is not a supply dock but is instead a series of supply piles right next to each other, have 1 chinook for each pile and make sure that each one has it's own pile. Though this will suck up what they contain pretty quick, you'll get more dough.

Supplies: (GLA strategy) 7 workers per supply source should work nicely here--though a considerable investment is needed, don't worry--you will get it back and then some quickly, especially if you are gathering from a group of supply piles. An 8th worker per source will make a small difference, but not that much. It's up to you if you want 8 workers.

Supplies: (China strategy) Like the USA, 2 supply trucks per source. However, unlike the USA, (if you have the money) you should consider buying a 3rd supply truck for each source, because it by far makes the biggest difference. However, don't do it if empties your coffers of course. Otherwise, buy that 3rd truck.

Army: (USA Strategy) Always (and do mean always) spend the required generals point to get Paladins and (later) pathfinders. Both of these units kick *** and you will thank me later. When you are ready to attack your opponent, a good strike force should have a good number of Paladins (or all Paladins, either way) backed up by a good number of Humvees, each one having 3 missile defenders (to take care of aircraft) and pathfinders (to slaughter infantry). Also upgrade the Humvees with TOW missiles. Also consider backing them up with either Commanches or Stealth Fighters (both good because Commanches slaughter ground units and enemy AA units can't see Stealth Fighters.) Buy as many of each type of unit as you can, even if it knocks your money down to 0. Then, of course, Attack.

Army: (China) You could start out by spending the generals point on either the nuke cannon or veteran red gaurds, but you can still win easily (using this strategy) either way. With China, you can pick either one of these two paths: Build a strike force of as many Overlords as you can, upgrading them with either propoganda towers or gattling cannons. Make sure you have 1 or 2 with prop. towers though, and they will be unbeatable. I can almost promise. The other way is to hole up in your base, building as many defenses as possible, and then building as many nuke silos as you can and blow your opponent to smitereens. If your a speed nut, the first way is faster, and the nuke strategy is not good against the GLA, because you always have to send 2 nukes to one spot to take care of the holes that the buildings leave behind. Or you can just build dozens of Migs with the Black Napalm upgrade and burn your opponent to ashes before he knows what hit him.
You might also want to try a combination of the three.

Army: (GLA) The GLA is a little different, but not much. Because everything they have is cheap, and therefore a little less deadly, you will have to build more of each unit to match the effectiveness of the other two sides. First of all, spend your first generals point towards Marauder Tanks. These guys are pretty good, though they still suck compared to the other two sides' tanks. Thus, you will have to build a lot. Do so. Build so many of these tanks you can't even select them all in one drag. This will kill your opponet quickly (unless he does the exact same thing.) Another strategy is to mass produce bomb trucks, upgrading each one with bio and high explosive bombs. Don't bother discuising them unless you are facing a computer opponent because a human will be able to tell they're bomb trucks, believe me. Send them all to his base, or use them to defend yourself if your opponent decides he'd better do something similar. Bye Bye opponent, or his army, in which case just do it again. OR you could mass produce SCUD storms in the same manner China would with Nuke Silos.

Okay, I'd better stop before this gets too long. And this is to you players who may think I'm an idiot after you read this. Go ahead and tell me--I myself am open to any suggestions. Just email me at mgc_clem@yahoo.com. And for those who don't wanna take the time to follow this strategy, go ahead there as well. There are literally thousands of ways to play and win this game. These are only a few. Go your own way--experiment! Then win and tell me how you did it.