This gist describes my solution to Matt Parker's puzzle #8:
My solution involves looking at the pattern of folds when viewing the folded stack from the sides. And then using some python code to generate all possible ways the folds can match up in a way that you will still end up with two rows of 4 sheets.
The list below shows all ways to fold a piece of paper, including ways where the top-left ends up on the inside of the folded stack.