I do some training exercises (for terran) on some ums micro map to not be annoyed by comp :
i just do F2 1a2a3a4a5a F3 5C6C7V8V9V 0S F2 ( c = tank in french version , V is vulture)
F2 is my "atack zone " with virtual groups of units
F3 is my factories zone
0 is my scan
I do it repetitively
I do aswell for tvt , tvz it s thesame but instead of 5c6c7v8v9v i got 5m6m7m8C9v ( C tank , V vessel) and in tvt : 5c6c7G8g9g ( g goliath).
Im not sure that it is that useful but it gives some automatisms to switch from making units to attack , only with hotkeys and f2f3f4