Ooh. I could write long and probably very boring things here…well, I guess that counts as a warning.
Anyhow, I like to think the best place to start is actually looking at what you have. It sounds almost ridiculously simple, but do you actually know how many corps/armies (or divisions if you feel like really fine tuning it) you have? I have found that my most embarrassing moments come when I’ve been running on autopilot and don’t really know exactly what I have; hard to make a plan with any reality to it if you don’t know what’s in the toolbox to begin with. “I want Kursk!” is well and good, but doesn’t mean much if you don’t resource it. And I think we’ve all looked at a secondary front and gone “huh, I probably shouldn’t have put all those troops there”. A simple listing of what you have and what is actually where does wonders for understanding what you have, and more importantly, what you probably should try to have in various places.
From there, big goals. “I want to be here by this time” type of stuff. A lot of that thinking has been done for both sides up to T17, but between two players in the same league, T1-17 are just the prologue. After that it helps to actually have a think about what it is you want to do. At times when I have a particular thing I want done, I name the operation. This sounds dumb, and obviously isn’t needed, but I find it helps keep me on track for force allocation and tracking the overall effort, as well as gives me short hand for prioritizing resources. If I say, want to destroy half a million Soviets near Voronzeh in November in Case Silver, then it becomes much easier to actually see if I have what I need in place - and if I don’t new stuff goes to Silver or I transfer forces from places that weren’t important enough to name.
Then it’s a matter of phasing. Understanding if this is going to be a four week plan or a four month one is helpful, and you just break it down into the digestible chunks you want done.
So, if I did it right (and that is the tricky part, isn’t it?) I know what I have, know what I want to do, and know roughly the timeline for it to happen. From there it’s mostly a matter of force allocation. Between reasonably equal players, the guy who brings crushing force wins. And if you can’t actually build a crushing force to do what you want, when you want it, back to the drawing board.