Well this might turn into a long essay so like... we shall see
A lot of my music writing is incredibly spur of the moment, half of the process for writing music is about the pre-game... recording every single idea and concept i come up with somewhere! I have all sorts of random project files, notes app pages, and voice notes filled with little snippets of ideas, maybe a theme i want to write around or a melodic idea, or maybe just a whole beginning/hook of a song i want to experiment on! But almost all of my songs start this way, for example one of my entries to this, Stuck In Time started from a recording I took on my phone in the waiting room before I had a meeting with one of my music teachers! This step is especially important as I am incredibly scatterbrained and having the ideas to start with makes the process a lot easier. It doesn't matter how strong/weak they are, they get recorded!
These ideas then often end up as the base for my projects, I put them in and start envisioning what harmony would look like for them, picking out individual notes i want to highlight and deciding how to shape everything around that. When I approach song writing like this, it tends to result in much more organized i guess more "poppy" structures centered around this main idea, with some B content before coming back to it. I also put special emphasis on coming up with some sort of contrasting line, whether that be an arpeggio or in the case of stuck in time the combination of that and some high pitched 8 bit swells to provide a rhythmic and melodic contrast to my main idea, as Im a firm believer in experimenting with how to use space. Adding something else for the listener to listen to that adds to your melodic ideas will make it even more impactful when you decide to take away, and helps to create a sense of movement and drive in even the slowest pieces!
However sometimes I dont start with a melody, i often start with more of an arpeggiated idea or a chord progression, and my challenge becomes "how do i turn this relatively abstract idea into a full fledged song"? This was how i started with my second (and arguably favourite) of my two entries, THE EARTH CAN'T HOLD ME. This idea started just with the main arpeggio that permeates the entire being of the piece, the looping thoughts that you just cant seem to make away, and around that I sat trying to figure out exactly what i wanted the audience to think when they hear it. Do I want it to instill fear? wonder? curiosity? I finally settled on more of an anxiety ridden feel, which is what lead a lot of my harmonic choices in this song. My harmony writing tends to be a lot more of individual lines then a bunch of thought out chords, every note is part of another "melody" line to provide contrast to my main ideas. This opens the door for me to more easily create very "dissonant" ideas with the explicit idea of driving forwards an idea because each line in the chord is meant to guide you to the next note, not necessarily the next chord. Im sure someone could tell you the harmonic purpose according to musical theory of the progression at 3:01 in TECHM, but this was made using this process of note by note chord composition, creating it so that every single changing note in a chord is part of a larger melody and not just thinking about "well i want an f major here, what extensions do I think are best to support this"? Obviously I tweak things up afterwards and clean things up a bit, but I think this process has been a huge staple in how I've made some of my favourite stuff to date.
Another thing im very much thinking about is how i want to develop my ideas, as dont in THE EARTH CAN'T HOLD ME I have a lot of repeated ideas that i spend a lot of time ruminating on, and I take an approach that I have learned from C418 that i call a more compositionally minimalistic approach, in his album Excursions C418 has many songs that revolve around a simple melodic fragment, repeating over and over again, and their development and intrigue revolves around the development of the sound itself and rarely the actual melodic content of the piece! Using shifting textures, dynamics, and timbres you will find you can create a lot more interest for an otherwise stale concept and then give it an entirely different feeling and emotion to it. I like to think in TECHM this develops from Unnerve -> Desperation -> Acceptance, with a slight somber undertone as the protagonist comes to terms and overcomes their looping spiraling thoughts.
This was just a lot of rambling but I hope it gave some insight into random pieces of my compositional process, specifically relating to my submission. If you have any questions always feel free to ask!