I fold the page in half, in half again, and in half again, rub the creases with the edge of my stapler or whatever I have, and then I usually just gently tear them down the creases to make eight strips. For this picture, I cut the strips instead. I think it is more efficient, but I like the slightly softer edge you get from tearing.
After I staple the strips in half, I take the two center strips (counting from the outside, the fourth strip from the left, and then the fourth strip from the right), and snip off about an 8th to a 4th of the end- give it a trip or a hair cut, so to speak. With the inner most strips cut just a bit shorter than the rest, you get less of an empty space in the center.
This is the part that is trickier to explain- you take your little book (a long, skinny book) of four strips, folded in half and stapled. You now, of course, have eight strips of paper stacked one atop the other. You will work with just four at a time.