Designing an irrigation system requires careful consideration of various aspects, such as the type and layout of the system, the water demand and supply, and the irrigation schedule and controller. Depending on site conditions, plant needs, and budget, you can select from various types of irrigation systems like drip, sprinkler, or subsurface. You also need to plan the layout of the system, including the location and spacing of pipes, valves, and emitters. Additionally, you need to calculate the water demand of your plants and soil based on climate, plant type, soil type, and evapotranspiration rate. Moreover, you need to determine the water supply available for your system in terms of pressure, flow rate, and quality. Finally, you should design an irrigation schedule that optimizes the timing, frequency, and duration of watering. You can use a manual or automatic controller to regulate the operation of your system. Furthermore, you can use sensors and smart devices to monitor and adjust the irrigation based on real-time conditions.