off topic:
Quote Originally Posted by Kobal2fr
- the reloading thing is (correct me if I'm wrong, TW gurus) a leftover from Rome. Basically, the longer you play, the more the game's strategic AI "remembers" what it wants/needs. When you save/reload, said "memory" is cleared and they act like nothing ever happened at all and they have to re-understand what their best interest is etc...
IIRC, back in RTW you could get factions who wouldn't speak with you at all to accept anything you offered, even becoming protectorates (vassals) just by a save/reload if the situation was right.
I sincerely hope this in not the case. I remember that so called save/load bug was a major gamekiller in RTW, because after reloading, the AI would completely forgot its plans, would turn its armies around and lift any siege. But IIRC it was fixed with the 1.2 patch. Let's hope it didn't reappear.

on topic:
as anyone else already said, do not rely on mercenaries, except maybe for spearmen, because the English ones are not worth much.

Stay defensive in Caen, and meanwhile conquer the British Islands. Don't let Caen fall, you will have hard time fighting French if you do.

Keep good relations with Denmark so you can trade with them, or make the quick conquest, but don't get into a prolonged war with them or you will lose a lot of trade.
Build roads and ports to increase your profit.

Don't forget to bribe the Pope every now and then, or else he will constantly nag you to stop attacking the fellow Christians.

If you can afford it, enter a crusade as early as possible, and establish a self-sufficient empire on the East. Beware the Mongols when they come.

If you play the long campaign, it might be a good idea to wipe out Portugal and Spain. Then you will have more manageable border and you can concentrate your forces on a smaller front in Central Europe.

All of this is based on my M/M campaign, it might not work on different difficulty settings.