Controlling the RPG
Solution 1:
Sorry there is no trick to this at all. The only advice I can give is to aim down the sights and crouch, this should limit idle sway which could throw your aim. Aside from that it's pure random chance as to where the rocket goes. There is no way to predict where it will go.
The best way to use it would be to crouch and aim down sight. Also stick to medium range shots. The further away the enemy the more chance there is that the rocket will miss.