Italy, more than any other power, needs to pick a theater and go. Italy has to be in active conversation with all other powers to figure out the alliance structure. I used to favor the Austrian attack outright, all the time, because it was the quickest way for Italy to become viable, but the problem I came across was less the Juggernaut risk (though it did burn me a couple of times) and more that it didn't leave me room to meddle.
See, no matter which way Italy goes -- east or west -- it needs to keep at least one unit busy meddling in the other theater. Italy above all other countries suffers from elimination in the middle game, because it either grows slower than the other survivors of the early game or is otherwise too slow to resolve its chosen theater before a hostile power from another theater hits it. Perhaps the best example is in the standard Lepanto, wherein Italy doesn't even get a second build past Tunisia until 1903 (unless you're fortunate enough to run a Key). There's a spare army left to do things, and while the risk of a brutal Austrian stab is there, very few Austrian players look to stab as early as 1902-1903 (and those that do find themselves dead at the hands of an Italian-assisted Juggernaut in very short order). That army is then left with nothing going on and no reasonable stab threat to ward off. So what should Italy do? Talk to all the western powers and figure out the alliance structure, then throw a monkey wrench into it without any regrets. Go hammer Marseilles unless there's an Anglo-German alliance (in which case, go to Tyrolia and threaten to hammer Munich until Germany changes sides). The ideal situation for Italy is a Franco-German alliance against England, because it can then use the army in a way which hampers the progress of the western alliance without bringing French fleets into the Mediterranean too early. (You'd think Piedmont -> Marseilles would be a casus belli, but it's little more than an irritant to a France in alliance with Germany, as it forces France to keep both armies continent-side, to protect against a German stab threat and against the move to Marseilles. And you'd be surprised how much removing the convoy option helps England against France.)
Conversely, if the decision to attack Austria is made... you're gambling a bit more. You're primarily hoping on your diplomacy to keep the west at bay here, because while attacking Austria can be done while also keeping a unit to meddle in the west, Italy must not only attack Austria but do so with enough force that it can hold position against a Juggernaut and get Russia to switch sides and fight Turkey (or vice versa). Luckily, taking on the role of "sole defense against the Juggernaut" by removing Austria and taking Austria's place tends to give Italy the diplomatic break it needs. Still, you want to cook up some chaos for the rest of the board. Here, an Anglo-German pact is the best news for Italy, because this removes the most dangerous threat to the Austrian attack (intervention from France), effectively creating a corner position for Italy while it pushes its forces in one large successive wave east. An Anglo-German alliance is also bad news for Russia, who will find the Juggernaut substantially less attractive if it means fighting a strong EG alliance solo while Turkey gets to munch on an isolated Italian player. (And of course Turkey gets to choose between a distracted Russia and undistracted Italy.) Finally, once England and Germany take down Russia, it becomes far more inviting for the two of them to stab one another instead of combining against Italy. But even if Italy isn't meddling as directly as it might in a Lepanto, Italy must balance the western game in a way which keeps any western intervention at bay until after Italy intervenes in the west in force first.
If, on the other hand, Italy focuses on the west instead of the east, it still has meddling options (although these become substantially more restricted). I would almost always dive into Trieste if I'm thinking of going west. Sounds counterintuitive, but it makes sense. If you're ignoring the east to start, it's going to develop into a 2v1. In 2/3 possible scenarios, Austria has an ally. The army in Trieste ruins Austria's opening game even by itself and is a serious enough cause for alliances to shift that it's worth the risk of pissing Austria off while setting up to move west. And if there's a Juggernaut, then you can move the army to Albania or Serbia and create a de facto Key Lepanto, using the extra army to forestall Austria's demise until Italy has the units off of French conquests to take on Turkey and/or Russia. Best of all, though, Italy convinces Austria to allow Italy to borrow Trieste in 1901. Provided that Italy moves to Tuscany and Tyrrhenian Sea in S01, the isolated move to Trieste is not a serious danger to Austria. And provided as well that Austria can move unimpeded into Serbia and Greece, it only needs four units for 1902 anyway before it can probably force Galicia and Bulgaria (and eventually Rumania and beyond) and get plenty of builds anyway. Italy's army again becomes an extension of Austria's forces as before, but this time Italy builds two fleets... and suddenly, with A Pie/F GoL/F WMS/F NAf, Italy has the best anti-French position it can possibly have, and as soon as A02, as well.
The point is pretty well-illustrated in all three examples: Italy has to hop on a massacre in the theater it chooses to move into, and has to forestall the resolution of the other theater as much as possible. All powers have to do this, of course, and should try to incorporate these principles into their strategies as much as possible, but Italy and Italy alone is able to make this the cornerstone of its strategy and explicitly move its units with these principles in mind. France, for example, would love to see the Balkans in chaos while it mops up the North Sea sector and cruises to 18 centers, but what kind of intervention can France really do to accomplish this? England and Turkey have that problem exaggerated multifold due to their more distant starting positions. Germany and Austria are both also capable of putting units in a wide variety of places on the board, but they typically must focus all of their units on one theater because they're prime targets in the opening stages. Russia is forced to fight on two fronts and typically plays with a similar perspective as Italy with regards to the Scandinavian sector (and more broadly the west), but Russia also tends toward concentration on one theater (the Balkans) until it builds up the strength to concentrate with great force on another theater. Only Italy has the capability (given its close proximity to so many theaters), the security (despite its central location, Italy is probably the least attacked country in the opening game), and the motivation (lack of easy expansion path means Italy already has to settle for slow growth, which incentivizes intervening with the other theater to slow it down too) to make this method of thinking the basis for its strategy.
Natty Light and Milanos, a game for bros
)
)
)
)
)