How many rounds you make factories?
What political slider moves you do before 1939?
Do you start make convoys and convoy escorts 99x1 at start (or when you have IC to do)
What kind your Air force be? Fighters and TAC?
how much you can do army before you need stop becouse you need manpower for war?
Usually until the end of 1937, allowing me to use the IC to build a good stream of CV/DD
I think there was an event that made it go from Dove to Hawk automatically, but it was gradual. As for mobilization, keep it down until war starts, to avoid the dissent hit. I also keep the free market slider close to full, for the lower production time.
Dont worry too much about convoys and escorts until 1940 at least. one 99x1 of each by then will do the trick.
For airforce, go with either fighters for long range, or interceptors for the bonus vs bombers but worse performance vs fighters, and honestly i dont use either TAC or CAS, since they were hevily nerfed, and i cant even pick them in group to tell them to do a mission (instead now i have to painstakingly pick each one, and by the time that ends i have to reorder them all. why could you do it before but not now? beats me). NAV is a great investment though, for you will be fighting a lot of ships, and they are a good help vs convoys too.
I play a different style than most people, and i build only ARM, unbrigaded. I discard my defensive doctrine and go for mobility from the start, then as soon as possible i research armor doctrine (im playing WIF2, by the way). Since oil is not an issue for allied armies, like the US or me, you can afford a full MOT/ARM force for yourself. However, since you dont have the massive MP of germany or the soviets, you need a small elite army, and ARM does a tremendously good job in that area. with 18 ARM you can pretty much encircle and destroy the italians in africa in a few weeks or at the most 1 monthish. Since ARM doesnt cost as much MP as infantry, and they also suffer less casualties, you can do a good job with those. To answer the question more directly, build until you cant build anymore, mobilize and keep building. By 1943/44 you can have a massive army ready to free (or terrorize) europe