Another feat of conservation...

...that I'm surprised never occurred to me earlier: I cut open the top of the toothpaste tube when I've squeezed the most that I can out of it, in order to get the last little bits of toothpaste that are stuck up in the edges out and onto my toothbrush. You get another few brushings that way, and you'd be throwing out the tube anyways, so it's not like by cutting it open that you're destroying it or anything. "Waste not want not."