Latest Obsession: Terrariums in a bottle

I was looking through Etsy and came across some adorable terrariums (like above pic). I've wanted to make my own (or break down and buy an already made one) for awhile now. With so many bottle shapes and plants the ideas are endless! I was cleaning out the neglected office and re-discovered a glass fish-shaped container that I bought as a gift for Robert years ago. It's really heavy duty...like 1/2-inch thick glass. As I was dusting it off the bulb in my head lit up. It would make an excellent terrarium! I even know the perfect spot for it. I told Robert about my brilliant idea and with a sad tone he said, "...but that's mine." I was like...whatever. It's been sitting on the file cabinet collecting dust so if he's not going to use it for something then I will. First I'll make a small terrarium out of a smaller glass bottle that has some interest. I hope I'll be somewhat successful regardless of me not having a green thumb. I've got some researching to do.