Conservation practice provides a considerable opportunity to generate new evidence to inform future decision-making. Substantial resources are currently invested in data collection and monitoring, yet too often these are ineffectively designed, meaning the data gathered contributes little to building an evidence base. However, thinking in advance about how actions are implemented, data are collected, and results are shared can greatly increase the usefulness of the results. Controls, comparisons, replication, randomisation, and preregistration can all improve the value of the data collected.