Provide tracking on at least 90% of domestic (US) orders

This applies only to US-based sellers. Tracking increases customer trust, decreases “where is my order?” emails, and facilitates the quick and fair resolution of delivery-related disputes. If your tracking rate is low, change your default shipping method to one that provides tracking (USPS Ground Advantage, Priority Mail, and so on) and make it a habit to upload tracking immediately after the purchase. If it is a cost issue, make small changes, such as slightly higher shipping rates or providing tracking as the standard option, while using untracked only for extreme cases.