Here are tips to push into Moscow. This plan does have some flexibility to either do more air force, land units, or naval forces with flex spending.
I1: Buy 1 mech and 1 tank. VERY IMPORTANT FOR CAN OPENING
G2: Buy minimum 10 fast movers on Western Germany
I2: Declare war, move into Eastern Poland
G3: Declare war, have main stack join forces in Eastern Poland; buy additional fast movers in W. Germany
I3: Move into Belarus. I have mastered the Northern route. Much easier to learn and thrive this option.
G4: Move main stack into Belarus, capture Novgorod
I4: Move into Bryansk
G5: Move main stack into Bryansk. Calculate how many planes are required to land there to prevent counterattack. VERY IMPORTANT! Have <~10% chance of successful Russian attack on your stack. If he wants to test his luck, let him.
I5: Calculate if Moscow can survive a G6 attack. If they can, move stack to Rostov
G6: Capture Caucasus and Volgagrod. Return air force to counter Allied invasions in W. Europe
At this point you can have a stack of fast movers head down to the oil fields, head east to China/Siberia, or come back to threaten Moscow. So much depends on how the Allies divided the money between the Atlantic and Pacific. Pretty much the only way that this general gameplan will need adjustment is if Russia decides to put a force in your way that is too big from your Italians to crush. Tossing away 6 Russian infantry to delay you a round should be viewed as a great thing for the Axis.
Tip 1) purchase 2 inf + 1 art per turn in France whenever possible. Combined with planes you will have a potent force to counter Allied invasion in Normandy. Maybe replace an inf with a mech if you want flexibility to support Italy
Tip 2). Purchase 2 inf or 1 inf + 1 art each turn and move with transport to Finland.
Tip 3). Have big air force that has the flexibility to attack into:
a) sea zones
b) W. Europe
c) Scandanavia
d) Russia
e) oil fields
Tip 4) try to keep Italy from being convoyed raided to death; if the Allies commit almost everything in the Med, that is great because it is difficult to send additional forces from the United States.
15-20 bombers create a devastating strike force when combined with some fodder forces. From an airbase in W. Germany or Italy, they can go almost anywhere.
Don’t worry too much about taking Moscow if he is flying up a huge number of UK fighters to protect the capitol. Eventually your flexible Dark Skies option combined with cheap units will overwhelm one of his defensive guard posts. Get your economy up to 80+ PUs per turn and good things happen to Germany, especially if he doesn’t have a solid foothold in Europe.