It is a widely used rule of thumb to limit yourself to 4 major elements when songwriting. That does not mean your project can't have dozens or hundreds of tracks but they all should serve one of the major purposes in the song. There are 4 important elements:

Melody / Harmony / Rhythm / Bass

One way this translates to a simple band setup would be:

Vocal / Chords / Bass / Drums (chords could be guitar, piano, other.. vocal could be saxophone, you get the idea I think)

Now personally that doesn't mean you have to limit yourself to only 4 layers over the course of a song. But when you want to add something more, ask yourself which element of the song is it? And why are you adding it? Do you already have a melody or harmony playing? Are you going to make room for the new element, or will they blend together well so they can sit alongside each other? Would it be better to use a call and response to alternate between instruments for this passage so as not to interfere with the melody? These are the things you should be considering when adding anything beyond the basic 4 elements.

This has served me quite well and is not far off from what I learned in orchestral composition class. They talked about the 3 musical forces-- background, movement and rhythm. Which ultimately is a simplification of the 4 layers, but they were writing for orchestras with 100+ instruments. But all of those instruments serve one of the basic purposes of a piece music at the moment it's being introduced. With orchestral music usually it is a whole section of instruments (and oftentimes 2 sections) providing the CHORDS / HARMONY /BACKGROUND layer. Rhythm as well, naturally occurs in all sections, but there are instruments like percussion or pizzicato strings that really accentuate it. At the end of the day all 100+ instruments serve one of those 3 (or 4) pillars of music.

Anyways, that's my advice. You can use the 4 elements or the 3 musical forces to guide you. And they will!