Conform to an office's working model. For example, take 20-minute lunches, leave domestic and emotional dramas at home and keep social phone chat to a minimum.
Be acquainted with people from all rungs of the ladder, from the boss to the post room.
Respect employee hierarchy, the elders and those with more company years than you.
Remember good email etiquette and mobile phone manners.
Always be discreet. Never discuss salary with your colleagues.
Shouting down juniors is embarrassing for everybody. If necessary, calm criticism has far more impact.
Respect confidentiality. Keep things to yourself when necessary and resist the temptation to pass on any sensitive information (professional or personal).
Illicit material spreads like wildfire so talk with caution within the office walls.
Beware of gossip. Gossips are usually presumed to be untrustworthy.
Never ignore printer paper jams or low toners.
Struggling in when sick will sometimes win you some points, but never if you're contagious.
Look keen and committed - the odd evening sacrificed to the office will score you bonus points.