R packages—bundles of reusable code and (optionally) data—are helpful for programming efficiently and avoiding the unnecessary duplication of your own and other people’s previously written code. You don’t have to want to be the next Hadley Wickham or Jenny Bryan—or even to share packages publicly—to benefit from learning how to build packages for your own use. A small local package containing functions that expedite your common workflows can shave hours of redundant work off your schedule. This workshop will cover how R packages are structured, how to add code and data to them, how to generate package documentation, how to check a package’s construction, and how to prepare the key auxiliary files that accompany R packages (description, namespace, and more). If you’ve written R code and thought, “These lines are giving me déjà vu…,” this workshop is for you. Eliminate redundant work, and save your most-frequent collaborator—your future self—time and energy by developing packages. To participate in this workshop, you should have R and RStudio installed and have basic familiarity with both. If you're unfamiliar with the basic syntax of R, we recommend participating in an introductory workshop or class before participating in this workshop. UVA Library Research Data Services offers a “Getting Started with R” workshop; in spring 2023, that will be offered on January 26th at 10:00 AM. Alternatively, you might consider Data Carpentry’s Intro to R series. We won’t review the fundamentals of R syntax in this workshop, but if you have questions about the material, or if you need help getting R and RStudio set up, you can reach out to Jacob (jrg2xq@virginia.edu) in advance. The workshop accommodates Mac and Windows users.