Figure 8 Knot -
The Figure 8 Knot - Follow-through, is used in Canyoneering for creating a "load carrying" loop.
Once tied correctly, the follow-through versus the bight will allow you tie the Figure 8 know when the LOOP you are wanting to attach to is already there.
From there, you will be able to tie it into things such as harnesses, backpacks, anchors, and even people (like a kid who is too light to rappel down).
NOTE - if you are LOWERING people, you will need to research into "belaying" people as that is the correct terminology and will need to find the best and appropriate way in doing so as it depends on the persons weight, the height of the rappel, how much rope you have, and what canyoneering descender devices you have with you.
Easy to inspect and untie, especially after it's been weighted.
It's been tried and true after 40+ years of rock-climbers using it to tie it into their harness.
It does take some time to understand how the knot is being tied. It's not extremely easy (but not hard).
Canyoneering Usage Examples:
Canyoneers can use this to lower injured or kid rappellers, along with lowering heavy backpacks down a cliff-side.
Below, I show you three ways on how to tie the knot, via:
2) GIF (animated picture that repeats itself with no-end)
3) Video (from Canyoneering101 YouTube Channel)