Start by gathering your tools, including the icing, cake mix, tips, and piping bags. Make sure you have enough white icing to make an even amount of each color. Look for blue and green shades that capture the muted colors of desert flowers.
Bake your cake according to the directions. If you're making multiple cakes, complete them all ahead of time so you can pipe your succulents in one sitting. Give the cake time to cool, then cover it with icing.
White icing makes the succulents stand out and creates a minimalist look, but you could use any color, including tan or light brown to replicate the desert sand. Cover the cake with a smooth layer, or take a more rustic approach with uneven coverage.
Divide up the icing evenly into bowls, then use the greens and blues to make different shades. If you go online or check your local hobbyist store, you might find a kit with colors made specifically for succulents. You can also experiment with different shades. Just make sure you start small; you can add more color, but you can't remove it.
Mix light and dark shades so you can give your succulents variety.
For each succulent, use the flower nail and a new flower square. Fill the bag with your chosen colors, then pipe a mound with tip 12.
Since Echeveria succulents come in a variety of colors, you can experiment with different shades of greens, blues, reds, and browns.
Switch to tip 81, then start your chrysanthemum by piping a cluster of long petals that point upright. Pipe the first layer of petals around this cluster, then keep adding petals in a circle around the flower. Start with narrow petals in the center that gradually fan outward, becoming wider and flatter. Don't worry about making them perfectly even--flowers are always a little imperfect.
Use the same color for the entire flower, or experiment with different shades.
Finally, arrange the flowers on the cake and fill in the empty spaces around the succulents. Use tip 363 to make small star-shaped plants that accentuate your succulents without drawing away attention from them.
With tip 6, make small dots on the cake for added colors and diversity. You don't need to fill in the whole surface: leave a little extra space around the edges of your cake so it looks like the succulents sprouted out of the ground, or only place the plants in a crescent moon shape and leave the rest of the cake plain or iced with white.