Final answer:
You should start your left turn from a one-way road onto another one-way road from the left-hand lane, following standard traffic rules and any specific signs or road markings at the intersection.
Step-by-step explanation:
When turning left from a one-way road onto another one-way road, you should start your turn from the left-hand lane. This is typically the standard rule of the road in many places, as it allows for a smooth and safe turn while also being predictable to other drivers. If you start from any other lane, it can lead to confusion and potential accidents. It is also important to follow any specific signage and road markings that may indicate a different rule at a particular intersection.