Instructions –

Materials:
Container. (You can use fish bowls, mason jars, flower pots, buckets, old lamp or anything you can think of).
Stones
Colored sand
Cactus soil
Shells, star fish, miniature toys and other props
Cactus, moss and succulents

Where to Buy:
Lowe’s and Michaels. 

Process:

• Start with a layer of stones. This helps with drainage so it is an important layer. You can add a bit of charcoal to control moisture too. 
• Layer the stone layer with sand and mud based on the look you are trying to achieve.
• Dig a tiny hole and place your plants from their original pots along with the mud. At this point it might tumble so handle carefully. Cactus can be very prickly so make sure you don’t hurt yourself. Wear your gloves to be safe. Cover with mud and you are done. You can use stones on the side to stabilize the plants.
• Decorate with your favorite props based on the theme you are going for. I used shells and stones. 

Prettiness factor:

• Color and texture: Focus on adding different colors and textures by layering different colored sand, mud, stones, shells and succulents. If you want the green theme then try going for tone on tone greens with different textures. Add reds, yellows and oranges if you want it keep it more colorful.
• Level Play: Different levels contribute to an interesting cluster so play with the levels by placing different lengths of plants and stones together. 
• Layer Play: Try layering with different colors and textures. Make sure that your layers are thicker so they show up clearly through the glass. My first layer was tiny stones that got completely covered. This was my first attempt at making terrariums so it was a great learning experience. Add bigger stones at the bottom and make the layer thicker so it won’t get covered completely and show through the sides of the glass.
• Theme Base: Alice in wonderland, rainforest. waterfalls, mountains, zen, garden or ocean, a theme will make it more interesting. 
• Pretty Props: Add mushrooms, start fish, rocks, rabbits or moss based on your theme. 
• Cool Container: Based on your theme, you could go for fish bowls, antique lamps or buckets. I absolutely love this mini succulent garden in an Altoids tin idea presented on Free People blog. 

Keeping them Alive:
Now this is the hardest part for me because I don’t have a green thumb. According to experts, succulents don’t need too much water so overwatering is the worst thing you can do. Spray mist lightly or use a straw to water lightly once a week.  


Here are some pretty terrariums that you could draw your inspiration from:
Beach Decor Whelk seashell Air plant
Lime Air Plant Terrarium
Another World Succulent Waterfall Terrarium
Extra Large Jar Terrarium with Bunny 
Exotic Red Dendrobium Orchid Terrarium
Modern Succulent Terrarium with Greens


Here is a video from west elm on how to make your own terrarium.