Really good video on how composers orchestrate harmony (Which sections play which voices of a chord) but these principles can be applied to layering synths too e.g not doubling the third (or if you do, using a weaker instrument like viola or a filtered synth patch played higher up so it has less weight for example) This lets your ear hear the quality of the chord without weakening it by having the third be more prominent than the tonic. Anyway, he explains more in the video
