Guys, for me as a sword and shield player, I face my shield to the character, the cursor is only a means to do that. I play as if I am the character, I don't face him straight on, shield on my side..., I put my shield between me and him, I would say my cursor is to the right on the enemy at that time. Also i use the cursor to rotate and twist my character so I swing my shield arm into position. As a shield player don't use the cursor as a target when blocking, feel your character and use the weight of the shield to get good rotation. Or if you are standing still, make sure you put your shield between him and you.
Also know your enemy's weapon, axes tend to hit you if you block the shaft as the axehead by-passes the shield. It is all about the positioning of your shield, The character actually tries his best to get to the best position to block but if you don't help him out by rotating and giving him bracing space, then expect your blocks to be weak. The blocking is one of my favourite things of the game, it is definitely not perfect and will need alot of work, but the blocking in this game is very similar to human reaction. The way we automatically and instinctually do things, but with experience and training we react better to anticipate blows. The only people that give me real trouble in the arena are sword and shield NPCs (The Ladies with the big shields), sometimes the 2H sword can be a pain, maces can be a pain, but never as hard as sword and shield.