Remember this:
Hitler, in trying to defend everything, could defend nothing.
I always try to be proactive in my sea and land defenses, but if you see the Allies attempting to land, pull back, build artillery and counterattack when the Allied airforces and navies can’t hit you. The exception is Germany, West Germany, Denmark. But you should defend 5 tt’s from the US (perhaps 6 depending on the Med): France, WGer, Ger, Den and Greece (and maybe N. Italy or Rome…)