Flexdashboards are a simple R Markdown template and make laying out dashboards (with or without interactivity from Shiny) very simple. For more information about flexdashboards, go to rmarkdown.rstudio.com/flexdashboard/. Creating a flexdashboard in RStudio is incredibly easy. First, install the package with install.packages("flexdashboard"). Then, just select from File | New File | R Markdown... | From Template | Flex Dashboard | OK:
As with most RStudio documents, it comes prefilled with the boilerplate code to make the structure of a dashboard. You can see the structure straight away if you like, by clicking Knit in RStudio ...