A few tips:
* Send diplomats and ask enemy factions for trade rights (before wars break out) in the beginning. If you're playing as mighty faction (England, France, Holy Roman Empire, etc.), you can even charge them for it. Although, this is related to point 4 (see below) If they reject, it's often because you don't have any markets, docks, etc (and therefore unable to trade)
* Also, you may want to ask for alliances. They will buy you time to plan your economy.
* Auto-resolve sucks. Save before auto-resolving and then reload and deal with the situation (if you lose, that is)
* If you take over a settlement, always sack it (really overpowered) unless it originally belonged to another religion (then you must exterminate) or public order will cause you trouble.
* Focus on stability early on: roads, mines, docks and all that. Also, churches for public order, squalor and whatever. Tax the shit out of your population from the very beginning, but keep public order in the yellow/green. It'll serve you in the long run.
* Make sure you use your free upkeep units. When selecting a settlement your "walls" or the main building (usually the first one in the slot) will tell how many you can use. Train them. Keep in mind that forts/castles don't have any free units.
* The AI's proposals are often useless. Don't get tricked into accepting something useless :P
They can't be trusted and they suck at what they do.
* Don't bother with merchants :p
Post edited September 13, 2015 by Tpiom