DIY Inspiration: Terrariums

I feel like everyone's been talking about terrariums lately.  My friend Dan made this really cute one, filled with succulents and little rocks and posted this photo (filched from his Facebook page), left, of it in progress.

While I haven't gotten around to making my own yet, I have been giving them a lot of thought.

Should I make an open one, like Dan's and the ones I have seen selling for a pretty penny at Sprout Home?

Or do I want to do something more enclosed and traditional - the whole self-sustaining system?

While I figure out what I'm going to do next here is some DIY inspiration to get you started on your own terrariums.

A really simple how-to on Design*Sponge.

Cute mason and jam jar terrariums on CRAFT.
 

A thorough how-to on About.com.

 And, of course, the Fairyland Terrarium that Martha and Julie Andrews made on the Martha Stewart show the day I shadowed the art department.