The base is original from the producer (chords and melodies), but is complemented with elements that complement the song that come from samplepacks, usually, vocal chops, guitars, wobbles sections, glitch effects. It is the standard in which most of producers work, in a project you will find MIDI files made by the producer, but also melodic loops.
I use a lot of 3rd party plugins by UAD, iZotope, Waves, Soundtoys and many more.
I also use instruments like Serum, Spire and NI Kontakt (Ultimate Bundle), but
I printed out all MIDI Files in the project, so if you don’t have one of the instruments, don’t worry. As for the plugins, I use them in my workflow, but if you’re missing some of the comps or EQs, you can easily use another plugin and get the same results.
I used some Drum and FX samples by Splice.
Instrument Vocal Chop
Sample pack Fabian Mazur - Vital Future Funk
Loop name ELX_VFF_108_talkbox_loop_stab_Amin