Other than learn by doing I can only suggest to watch the
videos by pishifat, he made some useful ones that can help if you're new to the topic.
Other than that the
Mapping/Modding Guide Compendium might has something useful for you too, although most of what's there could be outdated by now.
Also you could look at other 5 star maps of the same genre as your song, to get a general idea of what to do.
I'm not good at explaining this further, as I'm not proficient in the mode you want to map in, but I hope this somewhat helps you.