If you're looking a guide to making publication-ready data visualizations in R, check out the BBC Visual and Data Journalism cookbook for R graphics. Announced in a BBC blog post this week, it provides scripts for making line charts, bar charts, and other visualizations like those below used in the BBC's data journalism.
The cookbook is based around the bbplot package (available on Github), which has been in use at the BBC since March 2018 for creating graphics in the BBC News graphics style. Rather than drafting graphics in R and then relying another graphics tool or a design team for publication, R has been a "game changer" for the BBC. It offers more creativity and control while saving time and effort, especially when the chart needs to be reproduced every time the underlying data change. The BBC offers a six-week course for its data journalists internally, and you can learn as well with the free cookbook published by the BBC, linked below.
Github (BBC): BBC Visual and Data Journalism cookbook for R graphics