At one's own instigation, of one's own accord.
off the hook
Performing extraordinarily well.
off the bat
From the start; immediately; right away.
off the wagon
No longer maintaining a program of self-improvement or abstinence from…
off the radar
Unlikely to happen or be important in the near future, or tending to e…
off the deep end
Crazy, erratic, or irrational.
off one's nut
Insane, crazy.