Russian alliance dating
The Sealion is a powerful opening with relatively low-maintenance diplomacy requirements; aside from a successful Italian(-Russian) attack on Austria in 1901, it is likely the most rapid dismemberment of a power in the entire game, leaving a power with a single center after 1902 and possibly out of the game by 1903.
The Lepanto System, a joint Italian-Austrian opening system against Turkey, is named after the Battle of Lepanto in 1571, a naval clash between the Ottoman Empire and the Holy League (which at the time included the Spanish Empire, in Italy, and the Habsburg Empire, in Austria).
There's little the Sealion coalition can do if England realizes the Sealion is developing; the trick is to make sure that France (in S01 diplomacy phase) and Germany (in A01 diplomacy phase) convey their peaceful intentions to England very clearly and convincingly so that England doesn't catch on.(C.) The southeast: Both France and Russia could come into trouble in 1901 with such a commitment north.
Italy moving to Piedmont in S01 can cause France some serious problems, especially if it leads to France guessing wrong in A01 on whether to bounce Italy from Marseilles or not.
The first target is to either have Germany work in the west, while contributing a few armies against Russia or Italy.
Once one power in the East has fallen, the alliance is free to continue against the other (usually Turkey comes after Russia, then Italy).
Sometimes a full alliance against Russia, sometimes just a non-aggression pact, these two powers must stand back to back in the game.
A stab in this alliance spells doom for both, for attacking the most natural ally in the game results in wasting of armies pulled from other fronts.
France now wants to support Germany into the North Sea.
Austria and Italy also should coordinate to convince Russia that Turkey is going to the Black Sea, and vice versa; it often takes very little effort to get Russia and Turkey to bounce in the Black Sea in Spring 1901, but that bounce is vital because a Turkey which can get its fleet into the Aegean Sea by Winter 1901 can defeat the Lepanto without much trouble.