One thing I keep getting extraordinary success with is World Government. People get too focused on military fighting in information age and lose because of it, even if they are owning. You should really look for that light blue icon, if it's being researched by anyone then you have to think "The game has only two minutes left".
In pure conquest games, with no capital elimination, territory victory or wonder victory, then it's power is far more limited. But otherwise it sets the game up to end.
In fact, when the game enters Information age, you really ought to start thinking of the end. BHG put a lot of mechanisms in to make the game end, you have to find one of them before anyone else.
This is actually the least likely way. Using a combination of tanks, Infantry and MLRS you can overwhelm an opponent that you are tech up on. About the only time this works is in a game you are winning anyhow, you have already won in earlier ages so this method is just closure.
If you are going down this route then the future techs of choice are a combination or Artificial Intelligence and Global Prosperity, the latter more useful if you are slightly behind, possibly defensive
I read that one thing BHG noticed in RoN was that people weren't using bombers as much as they designed, so they made them more effective in TaP. One of the problems in using Air power is it's difficulty in use. Take the time to assign control groups, at least one for a fighter base and one for a bomber base. To order them, press "r" and left click. All new planes go to that point and all planes currently on missions will divert to this point too. Employing air-power to bomb the enemy back to the stone-age while harassing his army easily can certainly be a game winner.
This is the big one, the game turns into sudden death. When this research is started you have to act immediately. First priority is to see if you can kill all the enemy libraries to stop it. If not, it will be hard to stay in the game. When a WG player successfully takes an enemy capital this will cause instant elimination due t the "retake capital" timer being zero. This then has the effect of conquest resulting in all that players cities changing hands. Then another effect of WG kicks in, all cities are instantly assimilated so the territory also switches, also all wonders belonging to the defeated player also switch. The territory and wonder switch are likely to be enough to rack up a wonder or territory victory condition. Except now a 3rd effect of WG comes in to play. The timers for Wonder and Territory victory are zero, so it's instant victory. Game over.
With ICBM
A clinical strike, the only real defence is missile shield. The player with WG will also have ICBMs up (not nukes), his plan is to send a few infantry units to your capital, just before they get there, your capital will be ICBM toasted, achieving 2 things, the reduction of your city to zero points and the elimination of all defences, towers, army etc. When the small infantry force arrives it's early bath time. Possible defences are to research missile shield as soon as you see WG start. You can also max your attrition and station defences outside the blast radius to intercept a small assault force. Finally, station a few infantry near your capital and run them in immediately after the blast to cover while you repair the city asap.
With Special Ops
If the target has Missile shield up you can still achieve WG win by sending a special ops mission in. The best way to do this is to assemble a force of about 6 Special ops, 6 infantry, 2 generals and a supply wagon near the border. First set a general to ambush and the other to forced march. Then send them all to the capital; be careful that the force does not get strung out or you will lose the benefit of ambush and units are likely to suffer horrible attrition. Assemble the force next to the enemy capital first (you may want to set to hold fire to preserve the ambush though I have never found this necessary). Now select all your commandos and right-click repeatedly on the capital. As each charge detonates, the city hit points are halved, so even a Maya city goes down fast, finally, finish off the city hit-points with infantry to secure the win. This one really is a sucker punch. There is no excuse to let this happen as it is easily prevented by a good ring of towers, a couple of observation posts (SAMs) and a few garrisoned infantry. What is somewhat harder to stop is the entire army of the enemy turning up under ambush to do this mission. But at least if he does this he is placing his game at high risk and if his army is not at the front then you should place a bit more emphasis on home defence. Having a good responsive air fighter force can help you out here too.
With Bombers
Once WG is on the way, your main priority should be to keep your enemy capital on zero hit-points. A good force of bombers can keep the enemy capital ready for the take on a permanent basis. They can also keep SAM sites out of the area and kill any economy too by carpet bombing the area. Even if you can not achieve the WG win, the reduction of enemy economy, and his focus on capital defence should give you a significant advantage on the main battle front.
With Amphibious Landing
So many people forget about the water. If your capital is on the coast you are very vulnerable to invasion. People think that the sea protects them. This is only true in Age one. After that it is actually better for the attacking force as there is not attrition on sea, they have direct access to your capital, often from behind. Defences are not easy against this because naval power in RoN is very poor, even if you station a few ships/subs in defence, there is a lot of sea to cover and unless the navy is big, it wont stop a large force getting through. The defence against this is to build up your capital defences gradually through the ages, keep putting the odd tower down, observation posts and even a fort.
So the message here is when you get to info age, if there are any "cheap" victories to be had, make sure they are yours and not the enemies. Personally, my feelings are that people who regard these victories as "cheap" are being rather noobish. RoN is a strategy game and all these features were put in precisely to add strategic gaming to it, if some so-called good players think it's not a real victory then that is their problem, their screen will still display the word DEFEAT in big letters in front of them, regardless of what their tanks were doing to you 2 seconds earlier.
Above all, keep an eye out for that light blue tech icon.