The approach
Pick a marker such as a lamppost that will be the start point for your efforts, and as you approach it seated in the saddle, ensure you are in a gear that is a little uncomfortable to work with.
By the time you reach your marker make sure that you are working against a load that encourages you to pedal the full circle (see pedalling squares drill) and begin to pull on your arms to stabilise. If you are in a gear with enough resistance you should notice that on any ‘down stroke’, you are pulling on the bars on the same side. Your bars should stay still however, as you match the stability you create through your arms and core with the power generated by the legs.
With an increased awareness of this balance between the upper and lower body, when you reach your marker, stand up out of the saddle by pressing down on the pedal, and pulling on the bars. Try to create a smooth transition so there is no ‘pause’ in the pedal strokes, and you are able to maintain momentum.