The standard play for me as Italy is a Wintergreen. Make sure Russia goes to Black as to limit that area, and also to Gal and Ukr. Quickly scrap through Austria while making sure France goes north. Ideally, you want to have Greece in A01, even if you don't take Trieste. The best time to be done with Austria would be in 1903. By then, you want to have Trieste, Serbia, and Greece. During '03, you want to start moving your fleets to the Aegean/E. Med. Get R to go to Arm. Convince him to support to Con and Smyrna.
Meanwhile, build a front of armies in Tyr/Tri/Ser. Support yourself into Bul. Start going west in '06. Taking Munich would be nice. Dominate France with the other remaining western power (England, hopefully). Stab Russia with your line of armies.
18 centers: Italy (3), Austria (3), Balkans (4), Turkey (3), Tunis, Spain, Portugal, Marseilles, another one you pick off (Sevastopol, Brest, Munich, Edinburgh<---favorite :D )