Key concepts - Baltic fleet and Mediterranean fleet.
The Baltic fleet is vulnerable to UK air on the first turn. That is why the carrier is built. You do NOT build two fighters as well; you use existing fighters. (You need to produce infantry on that FIRST turn, so the infantry can be sent towards Russia on the next turn. Delay is a major problem).
Later on, you use German air and the Baltic fleet in a suicide attack on the Allied Atlantic fleet. The German Baltic fleet you attack with take all the enemy hits, leaving your fighters safe. (You conserve your air power because you can use it to attack Allied fleets off your coast or to attack USSR territories).
The problem with this approach is that a carrier is great defense for the cost (since you already have fighters), but lousy as attack fodder (so expensive). More on this in a bit.
The Mediterranean fleet is initially used to help attack Anglo-Egypt Sudan. Anglo-Egypt Sudan is crucial because once Germany has that, it can attack the rest of Africa. Less IPCs for the Allies, more IPCs for the Axis. Usually, you need to keep the Mediterranean fleet in the Med because the UK can counterattack with fighter and three infantry second turn, likely retaking Anglo-Egypt. (This continues for a bit, sometimes with help from the UK Australian transport).
Remember what I said about the Baltic fleet? You have another option; building three transports. Now UK has to worry about invasion, and the Baltic fleet is protected (if hit, you can take hits on cheap subs and transports while your destroyer whittles away at the UK air). If you send the Med fleet west, you can unite the German fleet on the second turn. Problem is, your transports won’t do much in that sea zone off France, and you have to run away quickly before the Allied navy and air gang up on you. Also, if you go to the Med, the Allied fleet can reinforce Archangel, if you go to the Baltic, the Allied fleet can attack through the Mediterranean (although it takes a long time for the Allies to mount an effective attack there).
Other key territories:
Western Europe. Early on, you defend with a small number of infantry, tanks, and all your fighters. (You will feel that your fighters are wasted there because they’re not doing much, but really, you’re stopping the Allies from moving transports into fighter range). Later on, around turn three or four, you move all your tanks east, and move a few infantry in instead. Still later, you abandon Western Europe except a few infantry (you cannot hold Western Europe against a determined Allied attack). By that time, you should be kicking down Russia’s door. What this means, of course, is that you should produce lots of infantry and artillery first and second turn; after that, you should build mostly tanks. The infantry and artillery from the first couple of turns and the tanks will hit the Russian front about the same time.
Caucasus. Once you take this territory with a medium-sized force, Japan should reinforce with most of its fighters. That makes it very hard for Russia to counterattack. Caucasus is great because you can put four infantry on Russia’s doorstep every turn.
You have to work together with Japan. The fighters into the Caucasus is one major move. Another place Japan may help Germany is against Africa around round two to four. Of course, Japan should also press into Asia, so Russia is attacked on both sides.