Do your best to sculpt keep the big blobs at least somewhat competitive with one another Likely culprits are Russia, France, Prussia, Ming, Arabia, and one of the Indian powers. Countries who do well at this phase will most likely dominate Vic2 and HoI4. It can be a fun romp trying to contend with their fearsome armies in the late-game, and it also offers a more competitive New World in EU4, but if you're in a bad position or otherwise unprepared they can ruin a save. * Decide *before* you start whether or not you want Sunset Invasion. * Playing by your traits (picking targets based on your character's opinion of them rather than their geopolitical value, doing random things as a lunatic, sending tons of gifts as charitable, going gavelkind as family patriarch, or giving away land and money to the church as zealous) makes the game real interesting, and the emergent narrative should keep you entertained * As was mentioned previously, randomizing characters is a great way to limit yourself and mess around with the geopolitical landscape to keep it reasonable for EU4 conversion Megacampaigns are you usually tricky both due to their propensity for unsightly blobs and for player fatigue (it's easy to lose motivation partway through the campaign because nothing cool is immediately happening).