Musical Purpose: Let the Constraint Write the Arrangement
The final and most powerful constraint is musical purpose. Before you design a single sound, decide what every sound in the track will do. Not what it will sound like. What job it will perform.
One sound carries the harmony. One sound carries the rhythm. One sound provides the texture. One sound delivers the emotional peak. That's it. Four sounds, four roles. Everything else is a variation of those four.
The harmony sound plays chord changes. The rhythm sound plays a pattern that defines the groove. The texture sound swells and recedes to create atmosphere. The emotional peak sound appears only at the climax.
Now apply your synthesis constraint on top. All four sounds come from the same two oscillators. All four use the same LFO rate. All four share an envelope template. The result is four distinctly different sounds that are unmistakably part of the same musical organism.
Layering becomes automatic. The texture sound doesn't compete with the harmony sound because they occupy different emotional roles. The rhythm sound doesn't fight the emotional peak because they appear at different times. The arrangement writes itself because you defined the purpose before you picked a single preset.
This is what deliberate constraint does. It replaces indecision with direction. It turns sound design from a shopping trip into a construction project. And it produces tracks that sound like you, not like the default settings of whatever synth you opened first.
The next time you sit down to produce, try limiting yourself to one envelope, one LFO rate, two oscillators, and four musical roles. You'll probably finish faster, mix easier, and end up with something more distinctive than you would have with infinite choices.