You can use either an open or a closed container for your terrarium. Because there is no drainage hole in the container it's really important to have a false drainage system. So you can add river gravel or rocks to the bottom of the terrarium as a drainage level. Put about one inch of rocks in the bottom of the terrarium. Add a layer of charcoal on top of the rocks and it will help to keep the whole terrarium fresh. The charcoal will help keep mold and bacteria from growing in the terrarium. Next add potting soil. For ferns and moss you can use regular potting soil. Put enough potting soil in to bring the rock, charcoal, and potting soil to one third of the terrarium. Next put your plants in starting with the largest plant first. Before you put the plants in prune off any dead leaves and check to make sure there are no bugs on them. Put them in and leave each plant some room. Do not plant them with any leaves touching the side of the terrarium. There's a lot of condensation in the terrarium and the water will cause the leaves to rot. Ferns are really good for the terrarium and you also need some kind of ground cover. A moss is good for that. You can add some other things to the terrarium like willow twigs and foam fake moss-covered rocks. There are a few do's and don't that are important to keep the terrarium healthy. Don't pour a lot of water into the terrarium. Just mist the plants and put in one or two shot glasses of water. If you put in too much water you can't take it out. You also want to avoid direct sunlight. Too much direct sun will literally cook the plants. Make sure you remove plant pests and rotting leaves as soon as you see them so that nothing starts growing in the terrarium like bacteria or mold.