[I have never used it against a human player, but it works ok against computer 2 v 2 on hard, with Ivan the terrible on my side (Ivan the terrible sucks by the way...... too much focus on economy no defence whatsoever)]Aaaaanyway back to the point.
1. The aim to get one over on the computer player is to rush through as fast as possible, aiming to get to the fortress age with generally 5 minutes or so to spare (this doesn't usually work against queen isabella i've found, she is a bit of a rusher aswell)
In effect scrimp on the villagers until you reach the fortress age. By the end of the discovery age I had 4 villagers on each resource. Basically after you have emptied all your crates you will have 300 food, 100 wood, 5 settlers and a settler wagon. So place 2 settlers and a settler wagon to food collecting, and the other three on wood. With your 300 food make 3 villagers, and get the first villager to build 1 house. Then with your other two villagers place one on food and one on wood. While your villager is building his humble abode, train another 3 villagers (you will not have that amount of food by now, just train them gradually). Set all 4 villagers to mining and arrange for a shipment of 300 food to come to you. By now your explorer should have built at least 1 trading post somewhere (have him collecting the settlers and resource treasures around the map, they are rather useful). In the age-up take the 500 food option, or the 4 cows if you want. I would recommend the 500 food straight away, because otherwise you have to wait for your cows to gorge themselves (although they make it worthwhile)
2. In the colonial age dont focus too much on your military, your villagers will still be close enough to be garrisoned in the TC. Build 1 barracks and train a few pikemen, they can delay the opposition while your peasants retreat to the TC. Build a market and research the woodcutting improvement, and the hunting one if your people are hunting for food. If you have the advanced mill card, this is a godsend, send it as late as possible, but at least one shipment before your villagers run out of a nearby food source.
Keep training villagers, and exploring. Keep training villagers until you have 8 on each resource. Build a house as necessary, and maybe train a few more pikemen, crossbowmen or two handed swordsmen if you can afford them. You should always have villagers training in the town centre (until you get the 8 on each resource). If researching an upgrade or making a few troops will interrupt the flow of this training, for however much time, dont bother getting it. By the time you are ready for the fortress age you should have space in your population for at least 50 people, as well as having 24 villagers (i generally make 25 villagers, so i can have one villager building all my buildings), and you should also have maybe 5 pikemen and 2 trading posts.
3. Ok once you have hit the fortress age really crank out your economy. You should have a few minutes to spare before your enemies catch up, and by now you should have a mill and a market and have research the mining, milling and woodcutting improvements to at least the 1st level. In the fortress age try to get 14, or at least 12, villagers on each resource. Get a fort wagon sent in (if possible) and get your explorer to build a 3rd trading post. Near this 3rd trading post set up your fort and a second town centre, if you cant get a fort set up 1 or 2 outposts as well as a barracks. At this 2nd town centre you should eventually set it up as a 2nd base, complete with houses barracks artillery foundry etc.
If, and only IF you want to get to the industrial age(believe me when i say it is not essential), do it ASAP, after you have done all of the above. By the time you begin the upgrade to the industrial age you should have probably 5000 wood and at least 3000 food and probably 4000-5000-6000 coin in your coffers. You will ask, why not age up sooner? because you will have needed resources to build a small defensive army in the fortress age, and by the time you get to the imperial age you will have at least 3 minutes on the computer, who stops in the fortress age to expand base and military.
Back to the point again. Once you are in the industrial age you should really go hells bells on your military. Chances are you have already been attacked and it has left you with a very sour taste in your mouth, as villagers are a pain in the a** to replace. Aaaanyway sometime in the industrial age you should get up to 16-18 villagers on each resource with all economic improvements researched. But now start to work on your military. If you dont know what strategy your opponent is working on, i would suggest this small attack group.
10 Uhlan, coupled with 5-10 doppelsoldners (depends on your economy), 15 skirmishers and 3 falconets. Causes quite a lot of disruption to an opponents colony for its size. Also i cant stress enough the strength of an imperial war wagon, and if you have some of the cavalry improvement cards, use them aswell.
The few key difficulties in the german civilization lie in the lack of a basic ranged unit, and the lack of Uhlan hitpoints. The crossbowman in my way of thinking doesnt count, they are easily slaughtered by anything except for melee infantry. The german civ really lacks a musketeer. And also one of the biggest pains in the buttocks are constantly replacing your Uhlan cavalry. You will find that even your Imperial Czapka (imperial Uhlan upgrade) are slaughtered no probelemos by enemy infantry. After a bit of experimentation you can find a strategy easily. To each his own.
Now this strategy involves a lot of sitting around praying to god your enemies aren't too aggressive, or they dont come after you with a massed army in the colonial or fortress age. But once you pull this strategy off, it is very VERY difficult to stop. You will be able to get even to the imperial age miles before your opponents: The AI usually stops in the industrial age, and does most of its military work there, only after quite a while there will they go to imperial. SO my advice is to ensure that EVERYTHING is ready, including your armies, before you go to imperial, because once you get to imperial the AI will have been provoked to go there aswell.
Sorry this was so long winded, and i would recommend trying it on easy or moderate against the AI to get practice first. Also a level 10 home city makes it miles easier with some of the cards you can get.