We always have a terrarium. It had only Peperomia caperata and it was getting too full. Yesterday I decided to redo it and I put completely different plants: African Violet, Peperomia columella, Drimiopsis sp, tiny little fern and some moss. I transplanted the Peperomia caperata in an old shoe planter that my friend V gave me a while ago.
To grow small and pretty indoor tropical plants that need high humidity is very hard to achieve in colder areas like here in Melbourne. To solve the problem, it is a good idea to grow them inside a glass container, or just simply cover the whole pot/plant with a clear glass bowl. If you have an unused fish tank, it will be big enough to grow larger plants to suit the size of the tank.
Terrarium can be completely covered (sometimes with a little opening for ventilation) or an open one. Personally I like the fully covered one as I grow tropical plants in it. For growing little cacti or succulents, it has to be the open one to have dry air and to prevent condensation.
Update November 2016: Having a terrarium had been trials and errors for me so far, and I ended up with complete overhaul after two years or so. I’ve learned that it is very important to select plants that have the same needs and the one that grow slowly. I have found it very hard with perfect plant choices and ended up with one dominant plant overtook and smothered the rest. Few days ago I started to create moss terrariums and I think they will be easier to manage in enclosed containers and quite pretty to look at.
Meanwhile, this 8 sided polygon terrarium is now having a rex begonia and a peperomia in it. I have to frequently prune the begonia to prevent it from getting overgrown.
To learn how to make a Terrarium: