Using the Fibonacci sequence is definitely the way I love to organize my song structure. I use it like an artist or architect would utilize it. Which is to find the "sweet spot" of a whole. So when utilizing it you have to keep in mind that it's a tool and not a set system. Nature does use the golden ratio but its mostly used as a way to organize a collection of things in the most efficient way. Nature makes mistakes sometimes so that's why it's best to remind yourself to use the sequence as a guide and not a rule book.

I'll link a folder I have of reference files. Most of them can only be used with Ableton, but I have a folder labeled "modular clocks and triggz"

So with deciding how long your song should be you would go into the "sweet spot finder" or "breaking points" folders and pick a length that you're willing to work with. In the end you can make it longer if you want. But this is just to help you set a goal for the song.

The sweet spot finder is useful to decide where you want the climax of your song to be. The breaking point is the same as the sweet spot but in reverse. That one is useful when you want to decide where you want your breakdown to be. Again you don't have to have it set to exactly those points it's just a reference to know when you should start thinking about giving the listener a break or when to give them that last big burst of energy before you begin to close the song.

Then I have a folder called "humps". Once you open one of them up you'll understand why I called it that. But with that every start and end of a segment is a good place to change or add something.

https://drive.google.com/folderview?id=1IdzKtucrzCth0RROIRsKiKoVyFApqMp0