Here's a 13-part video series on making great Real-Time Strategies.
Back in 2015, Game Designer and YouTuber Callum McCole from the GeneralsGentlemen channel had started a great video series dedicated entirely to the RTS game genre – What Makes RTS Games Fun. Now, over the span of 6 years, the series contains 13 fantastic videos where McCole discusses RTS design philosophy, flow and pacing in such games, different units and how to create and differentiate them, base building, balance, and many other aspects of the genre.
The What Makes RTS Games Fun series is basically a Klondike of knowledge for those game developers who want to create their own Real-Time Strategies but don't know where to start and what things require the most attention. So if you are one of such developers, we highly recommend visiting the GeneralsGentlemen YouTube channel to learn more about the intricacies of the genre.