The arms of a LEGO minifig are pretty difficult to model, because of all the curved surfaces that need to be joined together at different angles and the connection to the torso...I always like to break more complex shapes down into primitives (especially when I'm going to make a paper model out of it ;o) and then edit those into the more exact shapes of the arms.
That way, you can see how all the different curves interconnect, making it easier to "see" how you can make them into one, smooth arm-shape.
But still, this is going to be a difficult piece to model, so I'll probably need a few tries before I get an arm that is satisfactory... ;o)
Stay tuned!
