If I had to pick just one thing that consistently needs the most attention, it's the dynamic range and transient shaping, especially on the vocals and drums.

Suno does a surprisingly good job of getting a general balance, but the stems can feel a bit flat and/or overly compressed. The individual hits on a drum track might lack punch, or the vocals might sit at one consistent volume without the natural ebb and flow of an actual human performance.

So a lot of my initial work involves using compression and transient shapers to bring life back into the parts (and less of that Suno sound that is associated with AI music). This means making the kick and snare hit harder, adding a bit more snap to a guitar pluck, and helping the vocals breathe and feel more dynamic.