The first step is to identify the sources of your lessons learned, feedback, and improvement suggestions. These can come from various stakeholders, such as users, developers, testers, managers, clients, or reviewers. Depending on the type and scope of your documentation project, you may use different methods to collect and record these inputs, such as surveys, interviews, focus groups, usability tests, reviews, bug reports, analytics, or comments. You should also define the criteria and metrics that you will use to evaluate and prioritize these inputs, such as relevance, urgency, feasibility, impact, or cost.