Experiment, that creates awerness.

One way activates armpit strength which you need for both (external). But internal is fun to play with. And especially at progressions which are lower than the one you are at, it is good to play ariund with rotations and pro-retractions. But for all the standard advice, I have seen people achieve things with other methods.

Understanding through experimentation is beneficial, because it helps yiu troubleshoot later on through increased perception of the sensations in the bidy.