I've always been rather confused about how to set up a Jenga tower. There is a cardboard piece that comes with it that covers two sides and either the top and bottom of a completed tower. It's clear to me that this is supposed to help in setup, since doing it free hand leads to a less stable tower.
But how do you actually use this insert? If you use the horizontal side is on the top, it gets in the way of placing blocks and doesn't help much with stability (you would obviously take it off before playing).
If it's on the bottom, it's more stable, but you can't get it out when it's time to play.
So how do you properly set up a Jenga tower with the cardboard piece?