Well, browse the gallery, you'll get lots of ideas. A terrarium can be as simple or as complex as you want it to be. You can sit plants in their pots in the bottom of an old fish aquarium. That way you can have plants that need different soil requirements all in the same tank. Otherwise, if you want to have a planted terrarium, you have to go with plants that all need the same soil. Get a good compact flourescent light and a lid.

hi
here's my two cents. if the primary consideration is esthetics go with a setup designed to be a terrarium.
Unlike aquariums they look so much better and are more functional when taller than wide. look at pix of various
setups see if you don't agree.
if you haven't yet, do look at the "Dutch Vivarium" sites. They move terrariums into works of art .
I've been setting up terrariums for many years. and these are my main complaints about them.
Not enough access or too difficult. You need to be able to access every corner.
Not large enough Quickly became too crowded.
Too simple ,became boring. Too complex. many things to break down.
The main thing to do is decide
What type of terrarium and what do I want to keep.
Animals ,plants both, how much water and what does it do .
A budget never hurts either lol.
Take your time and look around there are thousands of ways to set one up.
gary