I only grow plants in my tropical terraria. I have a drainage layer of about 3 cm (just over 1 inch) of LECA at the bottom, with fibre glass window screen mesh over that, then a layer of about 1-1.5 cm (about half an inch) of coconut husk (the big chunky stuff) that has been soaked in water and then squeezed to leave it wet but not dripping. On top of this I put about 3-4 cm of Atlanta Botanical Garden (ABG) mix (recipe by Ron Gagliardo). This is covered by leaf litter - my preference is dried "Live Oak" leaves (Live Oak is a species of tree in the US - doesn't look like Quercicus Oak), and some dried magnolia leaves.

The recipe for ABG mix is:

2 parts fine fir bark
2 parts fine tree fern fibre
2 parts milled sphagnum moss
1 part fine charcoal
1 part peat moss

Aside from the mix being good for tropical plants, the layers I use seem to be springtail heaven!