In order to build a maintain a good relationship with a vendor, you should first establish the best way to communicate with each other. You should specify all your needs and expectations, while ensuring that the vendor’s demands are met as well. After studying samples of their product, you should establish an agreement on the quality of the product, order size, delivery dates, and payment options. In-person meetings during this process can prevent any misunderstandings from developing. All of this should be written down or recorded for future reference. You should arrive at the pickup spot on time, and make timely payments (installments or one-time payment). In addition to that, you should give the vendor enough time to produce the amount of products. For a large order, you should order at least months in advance since rushing the process can force vendors to not focus on quality control. This can cause tension when the products fail to meet your expectations. If the vendor proves successful in good communication, offering fair prices, and meeting all expectations, you can even offer to recommend the vendor to others.