I always liked terrariums but I hate it when they put objects that are not natural (like tiny houses, figurines, toy animals, etc.). I like terrariums as natural as possible. I came across with some good terrariums but they were very expensive. I tried to make by purchasing all components from the web but that was still expensive. So I decided to make one by using materials in my possession.
Step 1: The Container
I started with my daughter's old fishbowl. After all, it was taking some storage space in my garage. For good terrariums, you need a gravel bedding so that the excess water can collect at the bottom of the container. I collected some gravel from my garden and used it as a bedding.
Step 2: Find Stuff From Your Garden
I collected moss and moss covered rocks from my garden. You can also find plants that are suitable for your terrarium in the dark and damp sections of your garden (or somebody else's garden :) ). The easiest way to collect moss is to scrape the moss with a small garden shovel. You can also help by grabbing gently with your hand. Before placing anything to your terrarium, just make sure everything is insect-free. I recommend washing the rocks with a hose.
Step 3: Of Course, the Plants...
You need to choose plants that are compatible to each other. If you choose a plant that needs significantly more water that the others, probably you will kill one or the other. The same is applicable for lighting or soil PH. Just do some internet search to find the best plant for your terrarium.
Step 4: Join All Together
Be gentle while positioning your plants. You don't want to damage their roots. You may use a pair of tweezers if the container opening is too narrow or your hands are too big (no offense :) ). Don't forget to use gloves. If you have a container that has an opening at the side, place the most water thirsty plants near the opening so that it is easier to water the terrarium. After planting, don't forget to water. But avoid applying too much of it.
Step 5: Voila! Your Terrarium Is Ready
Enjoy your new terrarium! :)