Oh, you know....
A long tailed running bowline as a secondary that some top blokes taught me
... You know they had their secondary as you would in the head of the tree around the trunk
If you slipped you woulda had to of hoped to snag a stub... for it to catchya... I was amazed that even the well established climbers aswell as the climbers in the companies the boys (students) came from even climbed with that as a secondary (Including up palms)
Showed a few of the boys trunk walking and showed them how to use a figure 8 (rescue) for aerial rescue.