Data collection is a foundational process in research, shaping the validity, reliability, and applicability of findings across disciplines. This systematic review synthesizes existing literature on data collection methods, tools, and strategies, highlighting both traditional and emerging approaches. The review examines qualitative and quantitative techniques, including surveys, interviews, observations, experiments, and digital data streams, while assessing their strengths, limitations, and contexts of use. Special attention is given to technological advancements such as big data analytics, online platforms, and sensor-based systems, which have expanded the scope and efficiency of data gathering. Ethical considerations, data quality assurance, and challenges related to bias, accessibility, and privacy are also explored. By integrating insights from diverse fields, this review provides a comprehensive overview of best practices and evolving trends, offering guidance for researchers aiming to design robust and ethically sound data collection frameworks.