There are so many articles and videos on FM explaining what it is and its history, but I haven't seen any on how to use it. There are lots of algorithms, but it seems its hardly any reason to use one over the other except for where the feedback is (to create subtractive style waves) or the number of carriers. Its a chaos engine, and there are some gold in there, but nobody really knows how to find it.
If you know any source that gets into an actually useful FM workflow, please share!