Route from Aulon heading up through the trees, with some often slightly precarious stream crossings, then out across the open valley and then you can hitch a ride for a bit more vertical on the Aulon Telesiege (part of the Saint Lary resort so you need to have a lift ticket/season pass).
For the way home there are lots of options, you can come back down the same valley, or in this option I have dropped one valley further over.