I have one that is "in process". It isn't a sealed terrarium. I think of it as a somewhat 'terrarium/dollhouse/dish garden'. So far I've planted:
Inside terrarium: (1) malpighis cocagera, (1) selaginella kraussiana brownii
& (1) oxalis hedysaroides 'rubra' in little clay pot
Outside terrarium: (1) selaginella kraussiana aurea & (2) selaginella that are
bushier but I lost the tags and can't remember the names.
I mist the plants once daily with distilled water. This is my first try at this and so
I'm keeping my fingers crossed that the plants survive and flourish. I want to
add table & chairs and another colorful plant to the inside and more plants to
the outside. The violet barn sells their mini plants in 2.5" pots. The packaging
and transit time is excellent. All of the plants I've purchased from them have
arrived in excellent condition. See pic of my terrarium below.