red oak
Minister of Fire
I use no supports for the ends at all, nor do I do any cross stacking. I shorten the rows as I go up so that the shape of the row is more like a trapezoid, longer at the bottom and shorter at the top. The sides and the whole stack do not wobble or shake at all. Over time, I've had a few pieces fall, but it's been years since it's been more than a couple at any one time.