I produced weekly newsletters for Lacoste Japan, showcasing products and promotions. Email HTML is painful for cross-client compatibility, and it was even worse back then. Everything had to be images inside <table> elements. Each newsletter took 40 minutes to an hour, every single week.
After doing this long enough, I built a tool that generated most of the HTML code automatically based on the images. That brought the whole process down to about 10 minutes, including Litmus testing. The lesson: automate boring, repetitive work early. We spent far too many resources on these before I got around to it.