Mountains aren’t perfect, right? I ended up shaping each one with my hands, pressing the base onto the stone so it’d fit nice and snug. It’s messy, but trust me, it makes a difference. The trick is to keep the bottom aligned with the stone so they sit just right.
For my holder, I made four mountains, two big ones in the back and two smaller ones in front. Play around with it—depending on the size of your stone, you might want a different setup.