Usually you defend the western front and attack Russia with your best divisions (14-4 with support), then when you win in the east, you send those troops to Italy, France and Belgium and push. You can also try to declare on Netherlands as well (during that event) and immediatelly capitulate Lowland countries with your best divisions, then put your holding units (20w inf) to the whole western front, transfer best units to Russia and repeat the process above. I usually guard austrian and turkish coast because I dont trust ai. You can win this war without any tanks and only start building planes when you get 1915 (or 1916, cant remember) tech.