A mixing technique that’s commonly mentioned but not always understood is submixing. This technique groups audio signals together prior to the main mix bus and can help balancing and mix cohesion.
Long before DAWs with massive track counts became the norm, mixers began grouping together and processing similar tracks to help them balance their mix. Sometimes this was for convenience, but could equally be down to limited resources, and the need to share specific processors. Either way, it turned out to be rather good at getting the mix to gel, and certain mixers even became well known for their submixing methods (Michael Brauer is probably the most famous example).
In a DAW environment, resources are usually limited by our CPU’s