This essay provides practical advice about how to do transparent and reproducible data analysis and writing. We note that doing research in this way today will not only improve the cumulation of knowledge within a discipline, but it will also improve the life of the researcher tomorrow. We organize the argument around a series of homilies that lead to concrete actions. (1) Data analysis is computer programming. (2) No data analyst is an island for long. (3) The territory of data analysis requires maps. (4) Version control prevents clobbering, reconciles history, and helps organize work. (5) Testing minimizes error. (6) Work *can* be reproducible. (7) Research ought to be credible communication.