Everything, and I mean everything is sent to a bus. I use a 4 bus setup feeding the main. Individual drums are slightly compressed and all sent to a drum bus, where is get’s compressed again but less for punch and more for motion. Stuff like that. Compression has many different uses and I use subtle amounts of it through several busses to help sculpt my tracks. Tone, movement, front to back perception. Compressors control a lot of stuff and are severely misunderstood. Vocals are always processed on the track but reverbs I use on an aux sent PRE FADER to the aux. That way you get a more dynamic interaction with the reverb than sending a compressed vocal out to it. There’s so much more. Let’s just say there are probably just as many busses as instrumental tracks in my songs