Fairy gardens are usually housed in small containers. Think about how much space you have. If you're keeping your garden indoors, you'll need a smaller container. For an outdoor garden, you can use something larger.  Good items for an indoor container include something like a drawer from an old desk you no longer use, an old pot, or an old wash bin. Outdoors, you can use larger containers for a bigger garden, such as large garden plots or big bins. A fun idea can be to use a wagon so you can move your fairy garden around. Account for the types of plants you're planning on growing. Some plants may need extra drainage, so you should find a container that allows for some drainage if that's the case. Other plants can get by with less drainage. While you'll probably end up wandering from your plan as you create your garden, it's always a good idea to have a rough sketch. This way, you'll know how to best monopolize your space when planting your flowers. Make a sketch of your container and draw roughs sketches of where you'll keep things like the fairy house, decorations, and your various plants. Remember, nothing is set in stone yet. Think of this sketch more as a rough guide than a blueprint of exactly how your fairy garden will turn out. Part of the fun of a fairy garden is experimenting and finding fun, spontaneous decorations as you build. As you'll be adding plants to a fairy garden, find a location that gets a lot of sun. Strive for an area in your backyard that's free of shade or a space by a window in your home.

Summary:
Select a container. Sketch out your fairy garden. Find a good location for the garden.