1. Weight transfer comes first
The most important part of Cuban motion is the transfer of weight from one foot to the other. If your weight stays stuck between both feet, the movement will feel stiff or fake. If you throw the hip before your weight arrives, the movement will look disconnected. The action should feel like your body is moving over the foot, not like your hip is being pushed out to the side.
Step, arrive, settle — then continue into the next step.