I always play in GA mode.

I find that targetting only provinces that are GA goals (be it as homeland, crusade, Drang nach Oost, Holy Roman Empire, etc) and the ones adjacent to those makes a game that is a bit more realistic while letting you a chance to win on GA points.

It only works for "crusading" factions like the English, French , HRE and Italians (Imagine playing as the Danes conquering Sweden and Saxony and stopping there ..... only the AI does that ...). Tried it with Sicily lately and there is no way I could win that way since as from the Late Period you do not have any homeland point, only for conquest.