1. Clearly describe the demand for products or commodities: specify what kind of commodities you need, such as food, household appliances or office supplies. When describing the demand for goods, it is best to be specific to the details such as category, specification and model.

2. Determine the purchase quantity and cycle: specify the purchase quantity and frequency, and whether your demand is seasonal. This will help suppliers to understand your purchasing plan more accurately, so as to better meet your needs.

3. Determine the quality requirements: describe your requirements for the quality of the goods, including the appearance, durability and performance of the products. You can ensure that the supply meets your requirements by specifying the corresponding standards or certifications.

4. Requirements for delivery and payment methods: explain your preference for delivery methods, such as whether the supplier is responsible for door-to-door delivery or whether you choose to pick up the goods yourself. In addition, you need to explain your payment method and expected payment terms.

5. Explain other additional requirements: If you have other special requirements, such as supplier's credit rating requirements and after-sales service requirements, you need to specify them.

When compiling commodity demand, it is best to ensure that the language is clear and concise and the information is accurate and complete. This will help suppliers better understand your needs and provide suitable sources that meet your requirements. If you need to communicate with multiple suppliers, you can send the supply requirements to them in writing, so that they can better understand your needs and provide quotations.