The tips in this thread have helped me a lot, thank you all!
I'm using the 'big musket core with pikemen in front as anti-cavalry screen plus me and cavalry as a mobile potentially flanking or exploiting force' aproach, with great results. Still I get my ass whiped sometimes against lords with reiters and enough good cavalry, but if the quality of troops is similar, I usually can beat forces much bigger than mine.
What are your thoughts about caravan forts? I find that the AI is quite good at firing against them, so they dont seem to provide significant protection, while making the defending forces act cumbersomely and IMHO, not firing effectively. In my experience, when I tried to defend inside one, the result was bad, while I usually get great results when attacking them.