Mode spectator
Ctrl-M: Toggle floating player huds for the entire map (helpful to spot where everyone is)
Ctrl-P: Toggle Only Show Nearby Floating Huds
Ctrl-N to display a list of players to jump to
Left click to attach to the player in front of you
Left Click and Right Click to cycle attached player
Spacebar to detach
Shift to Fly Fast
Ctrl to Fly Slow
Mousewheel to adjust fly speed
Shift + f1-f10 to save camera positions, and f1-f10 to teleport to them
stopspectating for leaving