hehe, double team germany and ignore japan, i LOVE it when they do that :) you can chew up russia really quickly when your ignored.
seriously, as germany, try real hard to take as much land from russia and england without losing your offensive peices. in the early game ive had alot of luck with buying mostly infantry, with some fighter purchases here and there. lets face it, germany nearly always winds up defensive, and you need troops and fighters for that. i try to maintain at least one fighter per european country that i have, and one bomber for every 3 european country i have. works well, cause you can attack with a stack of troops and horde of aircraft, take a country, and still land your fighters in strategic locations. tanks come later in the game for me usually. but then, i usually rely on japan to do the real dirty work in taking out russia, and alot of the uk.
a friend of mine swears by german bombers. he buys all troops first turn, and 1 bomber, the rest troops for most turns after that, and strategic bombs russia. bombers are also nice to take out the occasional stray allied transport.