Meta-analyses provide researchers with an overview of the body of evidence in a topic, with quantified estimates of effect sizes and the role of moderators, and weighting studies according to their precision. We provide a guide for conducting a transparent and reproducible meta-analysis in the field of developmental psychology within the framework of the MetaLab platform, in 10 steps: 1) Choose a topic for your meta-analysis, 2) Formulate your research question and specify inclusion criteria, 3) Preregister and carefully document all stages of your meta-analysis, 4) Conduct the literature search, 5) Collect and screen records, 6) Extract data from eligible studies, 7) Read the data into analysis software and compute effect sizes, 8) Create meta-analytic models to assess the strength of the effect and investigate possible moderators, 9) Visualize your data, 10) Write up and promote your meta-analysis. Meta-analyses can inform future studies, through power calculations, by identifying robust methods and exposing research gaps. By adding a new meta-analysis to MetaLab, datasets across multiple topics of developmental psychology can be synthesized, and the dataset can be maintained as a living, community-augmented meta-analysis to which researchers add new data, allowing for a cumulative approach to evidence synthesis.