Austria:
Please note: this doesn't really work in gunboat.
The first thing you want to do is convince Russia that A/R is a better juggernaut than R/T. It is, because you don't have the Black Sea Discomfort Zone. If you have Russia online, you move to Serbia, Albania, and Trieste. Why Trieste? Just to check it down against Italian aggression. Sure, he can go to Tyrolia and still be a pain, but Trieste is the more annoying place for him to end up. If you end up in Autumn looking at Russia in Gal and Italy in Tyrol and Ven, you need to start talking and figuring out who's willing to take you on as a toady. In my experience, it's usually Russia and sometimes Turkey. The key is to realize that your three centers are MUCH easier to defend than anyone gives them credit for being, and if you can successfully bounce everything in Autumn 1901, either Italy or Russia will realize there's a little hot sauce in their cream puff. Also, if Italy gets aggressive at you, France is a good ally, and giving him the west side of Italy and Tunis is a great deal for you in the long run.