Resource Management is the key.

[TG Moses VI]

Well with the Allies you don't have to worry as much as not holding territories for more than a turn.  For example: UK attacks with her forces and manages to take Western Europe with three inf. remaining.  Of course it would seem like these 3 inf are piece meal to German forces.  But on the following turns USA also lands in WE reinforcing the territory with 10 inf.  As you can see, Allied coordination plays a huge role in these efforts.    

[Yanny]

Even better, Britain takes with forces, America and Russia bring all their troops and fighters in. This way they can hold it.

[TG Moses VI]

But where should the landing occur?  Eastern Europe.  Then again if Russian armies are in position a all out strike against Berlin would be something I would very much like to see.

[Yanny]

Eastern Europe could be followed up by Russian forces. Do that if the Russians are strong. Western Europe splits the German forces, do that if Russia is weak.

[TG Moses VI]

Ah I see.  Two different striking points will definately force the Germany forces to split themselves and keep them off guard.  But this requires that American transports are at least in the Canadian sea zone.  

[Yanny]

Where are your transports? Usually, I position them so they can pick up troops in Eastern Canada and deposite them in Finland Norway. This not only sets up a strike in any of Europe, but supplies infantry every single turn.

[TG Moses VI]

Well in one play style I use with USA I try to go straight for the jugular and try to take back Africa and Western Europe as soon as possible.  However in a different mindset I try to help my Russian friends as much as possible along with liberating Africa.  WE comes much later in the game (at least turn 6) when the Germans are retreating from Eastern Europe.  I guess your strat would definately apply with the later.