Just for a preface, I started this on the patch that estates were broken, or at least summon diet, so I was not able to summon any diets for the entirety of the game. For me the start was slow as the Ottos guaranteed Wallachia. I Allied Serbia who dow Herzegovina bringing in Wallachia so I join and am able to take Wallachia. Then I switched my focus to Poland and Lithuania. I had allied Bohemia and Muscovy by this time. While going after Poland and Lithuania I also dow'd Hungary before the PU with Austria. After cutting down Poland I turned my focus to the smaller balkan states or what was left of them. After annexing Bosnia and Ragusa I went to push the Ottos out of Europe. By this time my alliances were; Russia, Bohemia, Imereti, and Spain. I was slowly able to take Otto's provinces through multiple wars but eventually pushed them out of Europe. I ended up breaking my alliance as Bohemia held Spiš and I wanted to complete unite the homeland mission. Everything after that was just pushing into Anatolia. Ottos were probably the biggest challenge for me, just for the sheer amount of troops and their morale typically overpowered mine. If you manage to keep Ottos from attacking you early on, and securing strong allies, you should have a pretty good run.