Duped, Flipped, Averaged, Duped, Swap Left Right, Averaged

[trandoductin]

Manually, you leave bottom image at 100 opacity.
Set top image to 50 opacity.

But i used a script to do this that uses other scripts. https://gimplearn.net/viewtopic.php?p=1812#p1812

Then I usually bump up the contrast after getting the average, because most of the time the average looks low contrast.