It makes me kinda giddy when two different things I like come together. My terrarium collection is growing. I even recruited a couple of friends to make some with me last night. Fun fun fun.
Here is my recipe for covered terrariums:
Place a layer of pebbles for drainage on the bottom, a thin layer or horticultural charcoal (to absorb odors), then a layer of long strand sphagnum peat, to stop soil from seeping into drainage area of pebbles. Put in a few inches of pre-moistened potting soil and insert your plants, ideally without them touching the sides or top. Add trinkets and/or tchotchkes, to taste. Add very little water before placing lid on top. Then, admire and neglect. i.e. no need to water again for a long time, and when you do, a fine misting or two capfuls of water should be enough.