Observatories need to measure and evaluate the scientific output and overall impact of their facilities. An observatory bibliography consists of the papers published using that observatory's data, typically gathered by searching the major journals for relevant keywords. Recently, the volume of literature and methods by which the publications pool is evaluated has increased. Efficient and standardized procedures are necessary to assign meaningful metadata; enable user-friendly retrieval; and provide the opportunity to derive reports, statistics, and visualizations to impart a deeper understanding of the research output. In 2021, a group of observatory bibliographers from around the world convened online to continue the discussions presented in Lagerstrom (2015). We worked to extract general guidelines from our experiences, techniques, and lessons learnt. The paper explores the development, application, and current status of telescope bibliographies and future trends. This paper briefly describes the methodologies employed in constructing databases, along with the various bibliometric techniques used to analyze and interpret them. We explain reasons for non-standardization and why it is essential for each observatory to identify metadata and metrics that are meaningful for them; caution the (over-)use of comparisons among facilities that are, ultimately, not comparable through bibliometrics; and highlight the benefits of telescope bibliographies, both for researchers within the astronomical community and for stakeholders beyond the specific observatories. There is tremendous diversity in the ways bibliographers track publications and maintain databases, due to parameters such as resources, type of observatory, historical practices, and reporting requirements to funders and outside agencies. However, there are also common sets of Best Practices.