1- Not sharing good food with colleagues. They can smell and crave for it.
2- Flirting with married males/females on cheap purposes. Whole office knows what is going on and your all family reputation goes in mud in one go.
3- Discussing about their kids problems in front of childless colleagues.
4- Planning personal outings in high tones with few colleagues in front of other colleagues.
5- Parking vehicles in others designated parkings without taking their permissions.
6- Taking office stationary to home.(Nobody is blind, they know what you doing, ok?)Same with printing own stuff on office printer.
7- Asking a person, distributing something good, to give you extra for you family.
8- To ask lift/car pooling directly without considering their own schedule.
9- Calling colleagues on holidays to discuss office matters for long minutes.
10- Asking colleagues direct questions about their private/personal life in a decent manner and later on spreading it to widest level possible in hush hush mode.Now a days HR knows well and degrades such employees continuously.
11- Wearing dirty shoes and stinky/smelly clothes to office regularly.
12- Eating raw onions or garic based foods and not using mouth fresheners afterwards.