There are many things you should never do at work, but here are a few of the less obvious:
1. Don’t insult anyone. You never know when you will need them to help you.
2. Don’t talk about politics or religion. These kinds of conversations are divisive and political and religious debates are unwinnable. These are subjective topics with no right answer – ironically, everyone with an political or religious opinion seems to think they have the right answer. Don’t even go there.
3. Don’t fall in love with your coworkers. Go into work with the mindset that you are there for business. If, for some reason, you still manage to go crazy for a coworker recognize that you may need to find another place to work if you decide to pursue the relationship. Many companies don’t like coworkers having relationships because of the conflicts of interest that arise.
4. Don’t screw your coworkers. Especially if they are married. Do I really have to explain this one? Still, it happens more often than you'd expect and I have seen careers ruined because of tarnished reputations.
5. Minimize the profanity. Highly-selective swearing can be effective in the right situation with the right people. However, swearing properly is a skill many lack. Those who don’t do it properly lose credibility and sound like umeducated buffoons.