it's imperative that you find some alone time in the day (morning bathroom stalls work), and privately curse the shit out of everyone you work with; not just the competition, but your assistants as well. make faces, be stupid and unaccountable. you have to let it out, to offset the 'normalcy' you presume amongst your co-workers and clients the rest of the day.
this tip assumes you work in even the slightest competitive, backstabbing, and semi-stressful field.
this childish act holds no logic, yet unwinds your spirit in quicker time to any sort of cerebral pause and logic-based questioning.