Fold a paper into [quarters, sixths, eighths].
Make a continuous line from one point along the folded edge to one point along the other folded edge. The line can not cross itself.
Lay your folded paper on top of a sheet of chip board or other material. Use a pin to make holes along the line. The holes need to go through all of the layers, but not through the board material.
Unfold the paper.
Construct the lines using the holes as guides.