How do people get more efficient at getting headshots? And how do they know (roughly or precisely) at what hight to aim in order to maximise the chance of getting headshots? I've been trying to use objects in the map (which I've read is how...

Escalation is a mode that you don't really have to think while playing. Sometimes I just want to play a fun laid-back game after a long day and don't want to think much. With escalation, all I have to do is blast some music and shoot people...