Breathing, beat boxing, rhythmic breathing, intonation, dynamics, stretching, rhythmic dancing, and drumming to improve rhythm, improvisation, repertoire, acting, and laughing:)
I find that isolating the aspects of singing is more effective for progress. Improvisation is the best way to understand your voice, and rhythm is the foundation of music. One of my great jazz teachers told me that you can play any note, as long as it’s at the right time. Improvisation increases your musicality skills infinitely faster than traditional exercises. Check out my SoundCloud All Songs playlist, and my YouTube playlist entitled AdanaC Technique-Technique (95% of my music is improvised). I’m warning you though, it’s pretty heavy. Maybe skip the running, walking, and jogging videos in that playlist;)