I'll start, granulizer synths, Quanta 2 drastically changed the way i produced, from creating heavenly textures and otherworldly sounds. Discovering Granulizer Synths really upped my production sound. Back then i would just pick up a pad preset and just add shitloads of reverb to it. Now the ambient sounds i can create with a Granulizer Synth is on a whole nother level.
Resampling is also a neat thing I discovered, as a newbie producer, this changed the way i make melodies, resampling the midi i created and chopping it up allowed me to create really unique melodies i wouldn't have otherwise created if i just stuck to creating melodies in MIDI. I also have more control and i can manipulate my sound more freely.