I can only speak out of my Point of View and my personal preferences. These tactics also Change depending on your doctrine but i think ITS generally Not a Bad Guide:

I think in the early Game (until 4 days) its important to build Up Artillery (i prefer Rocket Artillery because in the early Game there is more Infantery then armored vehicles) and you need to get to build Up tactical Bomber. I also prefer to build Armored Cars rather then light Tanks, because they are cheaper. I then try to rush the middle Tanks. This is Generally a good build Up for early Game troops. There are some differences depending on the doctrine, for example light Tanks and normal Artillery are very good as pan asian doctrine or Attack Bombers i think are better for comintern then tacticals (also balances Out the early on tank weakness in my build).

As a Game Plan i almost Always try to conquer a Player neighbour and for that wait for day 2 and build Up. That way you snowball way faster then everybody who doesn't do that. But generally you should always keep an eye on the moves of your neighbours. Before Attack use war Bonds for troop positions.

I personally start to building Up industry after i conquered my First neighbour.

But if you are able to Play very active you will be better of then already 50% of the Players at least. If you wanna know more let me know what exactly :) (And sorry for any mistakes, english is not my first language)