Small Succulent Terrariums Rule
The glass is only about 6″ across, a small globe with legs and a hole on top. These things are hard to photograph. I hope you can see everything in there.
The succulents are planted in soil. A small bit of charcoal at the bottom, sand on top, and then I push the tiny cuts through the sand and into the soil, using my tiny fingers. I mean using long thin tweezers.
Tiny sempervivum cuts will love it in here, but the crassula cuts will eveually outgrow the sphere.