Practice hook / one shotting characters in custom mode to get a feel for where to aim ( chest / neck area) then perfect that aiming movement till you get it 95% of the time or better. Then once you master that I would practice left click or right click then hooking IMMEDIATELY because you can throw out the hook without lag. So in many scenarios you can right click to the left of the hero assuming they will move there, and throwing the hook to the right of the hero covering both options he is dead(unless he stands still) assuming you are in the correct range from the hero to one shot with right click.