In my experience, soldiers tend to miss more based on the distance rather than how far to the right or left they should shoot. I find changing distance to be possibly even more effective than going from left to right.
When a soldier bombs in to try and kill you they will probably shoot all of their rockets as fast as they can before he gets frag'd by your team. Take advantage of this and time your dodging with his predictable firing speed
be aware of all of the possible ways a soldier can get splash damage on you.
REALLY IMPORTANT INVITE ILLUMINATI MOVEMENT TIP
when u c a rocket press one of the movement keys to to move out of the way. remember to actually dodge buddy.