Another way to get plants is to watch for sales and swap meets of local clubs. You can sometimes stretch your budget this way and have a lot of fun meeting succulent enthusiasts. The coarser such material is, the more it will improve drainage. Succulent growers use a wide variety of soil recipes. There are all kinds of favorite ingredients and additives, each with its advantages and disadvantages.
Most species are tolerant of different soils, as long as the mix provides excellent drainage.
Once you've gathered the container, plants and soil, you're ready to start. Putting together the dish garden is a lot like flower arranging. It's good to get an idea of the layout before actually starting to plant. If the container is going to be viewed mainly from one side, taller plants go in the back. Or you could put tall plants in the center and work outward, placing small species at the edge and letting trailing ones spill over the rim of the pot.