After playing the 1914 scenario about 8 times, 6 as the CP and twice as the Entente, (and losing my first five attempts), I think I've finally sorted out the CP opening, or more accurately *a* CP opening that works for me against the AI pretty consistently.
The trick I find is to get belgium out of the war fast, and that means timing your attack sequence such that you take out the garrison in liege, but still leave two units (an infantry and your cavalry) with MP to burn.
Push them both into belgium and get hits on the infantry in the capital. If you're lucky it should be at 5 strength at hte end of your turn, leaving your opponent with no unit to garrison in antwerp. A 5 strength, yellow, infantry in antwerp can be taken on teh bounce, clearing your flank for a push down towards Paris.
In my experience, if I run this opening, more often than not, I get Paris and a french knockout. If I screw it up though, and let the belgians get a STR 10 infantry into Antwerp, I have to burn off too many forces screening it to push Paris well.
The first few times I tried this, I tried to take out Serbia fast, and screen the russians with a few garrisons in fortresses and just enough german reinforcements to hold the koingsberg/danzig line. Problem is that the Russians wiped my screen pretty consistently and rushed into eastern hungary, forcing me to pull more and more troops off... all in all not good.
What seems to work for me is to screen the serbs with a line of garrison units and leave them to rot until the Bulgarians enter the war. Then use the austrian mobile army and most of the reinforcements to make a blitzkreig on Warsaw on mobilization day. Between the forces Austria can bring to bear, and hte east prussian garrison, you can have warsaw under pressure the first turn after mobilization. Doing so drawns the russians to you, rather than letting their mobile force blitz around gobbling up your garrisons (plus the early russian garrisons are so weak you are almost guaranteed to get warsaw on mobiliation +2.
First few games, I figured I was "ahead" and didn't build up many units beyond a flurry of garrison units on turn 1 and 2. I spent most of my early income on A) getting an artillery for the austrians, and B) ramping up German shell production a few times.
This seemed like a good idea to me since those were both investments that would pay off long term, while troops would only be a maintenance nightmare that I'd ultimately regret building.
I'm thinking now that was based on a false premise; the best investment the CP can make in 1914 and early 1915 is to end the war, so the best thing I can/should do was to build up infantry and garrison strength sufficient to keep the pressure on. If you get Paris, the french are a mop up. Even if you don't get Paris, you can go defensive in the west and rack up kills in the east against the russians.
If you starve yourself of troops though, the western front calcifies, and the eastern front opens up when the russians start grinding you, so you end up spending a pile of money on maintenance and repair.
What do other people tend to do early in the war?
What are folks winning/losing with?