Quote Originally Posted by saint242 View Post
Definitely use artillery to knock down the walls. Having your units have to climb the walls while being shot at, and having them fight hand-to-hand is never good. Make at least two good breaches in the wall, and attack one with a smaller force to draw in the enemy. Then push a larger force through the second breach and hit the guys defending the first breach from behind. Or just grab the central flag.

Once you get Explosive and Carcass shot for your howitzers, assaulting fortifications is even easier. Put a couple holes in the walls and the enemy infantry will rush to block it off. Before you even move up your infantry, just start dropping bombs and fire down on them. Enemy cavalry may sally out to attack your artillery, but if you're using howitzers, you can safely position them behind your infantry line, effectively neutralizing any cavalry charges.
My approach is different, but it was not tested in multiplayer.
Do not break walls you will have to repair them :-)

focus your cannons on the one side/corner whatever. use small skirmisher force to rake defenders. They often sally to get your token force.
At the same time from the other side move dragoons or light infantry to the opposite side. Dismount and climb up. You are in.
If defender did not left units inside the fortifications are yours. And the main door button too. You got defenders in the open between walls and your army.
And wall mounted guns are unattended. you just switched from siege to "regular" encounter.