On counter-scouting...

Let's say you've decided not to rush, instead you're going to boom.

You know that you need to scout, and so you send yours off to see what you can see. But, you know that the enemy is likely doing the same thing, so what can you do about it?

For starters you need to realize that unless you have a large enough army waiting for the scout when it arrives, that scout is going to see some of your operations before it dies. So what you need to do is make it as difficult as possible, hopefully forcing the enemy to do more micromanagement of his scout than you have to do with your citizens/army/buildings.

Now, when you start a game with default settings, you should see that you have a library and three farms. These buildings, unfortunately, are clustered around your capital city. It's annoying when nuclear blasts take out more than just your cities. Any buildings you construct should, in my opinion, be built as far out as usefully possible from the city.

So, the first couple of buildings I go for are farms, which I build away from the enemy, and as close to the economic border of the city as possible. Doing this does a few helpful things, it keeps at least two citizens away from the main cluster of starting buildings, and so might escape the notice of raiders. It also gives you a bit more sight towards the rear area, where a pesky scout, or worse, an army, may make an appearance. The more time you have from the moment you spot the scout/army, the more time you will have to react to it. You can use any building to do this, markets and temples are always tempting targets, so placing them away from the action is a good idea.

The next thing to consider is placing any unit, that you are not planning on using immediately, into garrison. This allows towers, forts and cities to attack enemies that pass by, including those annoying scouts. This is espcially true of barracks units, if that scout can't count your troops, then the enemy cannot tell how well an attack will succeed. This can cause the enemy to think twice about an all out attack on your capital, the longer you can keep the enemy guessing, the more time you have to age and boom. And, the scout risks a quick death if it strays too close to that tower or city that has a few archers in it.

Placing your second city is an important decision. Many people like to build towards the enemy, since this can make things easier to do, the borders push harder, troops can be built closer, and that city can provide a buffer if things go wrong. Myself, I prefer to build off-center towards the enemy, about 45° either side of the center line. If the enemy scout barrels right up the middle, then he'll likely miss my second city, giving me more time to accomplish what I set out to do. If the enemy scout goes up one side or the other, then there is a 50% chance he'll miss my second city. Either way this buys time.

Building at least one tower early on opens up the option for attrition, which can deter non-scout units that are scouting (like a chinese citizen rush), and allows you to use a few citizens to kill any scout which wanders too close.

And lastly, you could give the enemy a little of what they want, which might make them lazy... by making the barracks easy to find, the stables you've built out of the way might remain hidden. That tower built prominently in the middle of nowhere might make the enemy wonder what else might be nearby. A few light infantry heading in the general direction of the enemy might make them use their scout(s) to find out what you're up to, and allow your light horse raiding-party time to pull off surprise raids.

As mentioned above, that scout will eventually see what it needs to see. All you can really do, I feel, is waste enough of the enemy's time micromanaging the scout to stay alive, without wasting too much of your own time. Occasionally you'll get lucky, and you'll be able to gang-beat their scout to death with a group of citizens... but don't hold your breath on that.