You just asked how the universe came into being. Before you start looking at how to recreate a drone, you need to understand or discover what a drone is and where it came from. Sound is created and combines, separates again, includes many individual components, nuances and moods. You can go out into nature and listen to the wind making the leaves of the trees fall, in between a crackling of branches, an animal moving. You can listen to the sounds in the city, what do you find in them, how many components move at different intervals or only once. Listen to the cars, the night wind or the wet streets, the rise and fall as modulation. Sit by the sea in winter and listen to the lonely expanse beneath the snow-covered mountains, the crunch of the surf, the unevenness of the winds. The cause is always the instruments, they play the sound. But the effect is the overall picture of the surroundings. You find echoes and reverberation everywhere. With an instrument, the sound is picked up by the wind and carried on. Of course, the wind can have turbulence or be completely silky or absorb everything. In a cave, the sound is reflected enormously, it can certainly also bend. A drone is sound and it change to each other and within itself and through expansion and reflection. So look at your instrument, how many sounds/layers does it play and in what sequence to each other. Above all, which modulations are already in the sound. You can modulate through technical interventions and through your own interventions when you play the sound. In principle, you should simply start from an INIT sound and then turn the knobs. Or play a string instrument and get to know the many elements of playing. Or explore the simple tones of the piano in connection with reverb. I think who creates a drone that lives and breathes (however they conjure it up) is close to building the universe.
