projectInit is an R package that helps you load a project-specific R workspace. It reads environment variables to coordinate your working directory, code location, raw data folders, and output folders. It then provides universal directory functions so you don't have to worry about keeping track of annoying file path bookkeeping, but can concentrate on your R code instead. This lets you easily work in different environments and share inputs and outputs across sessions and across users.
devtools::install_github("databio/projectInit")
View the vignette to see how to use it.