Lighten up! Okay, that may be hard advice for anyone who hears that phrase on the job, but humor in the workplace is more than possible and without getting served a pink slip either. A good laugh now and then will do wonders for you, as smiling and laughing lowers your stress levels (a godsend in the sales industry), wins you a friendly reputation, and helps your usually tense coworkers and bosses unwind (and thus not take their frustrations out on you). Humor on the job does plenty for your career, but there are some things to know before becoming the office comedian.

Keep in mind that there are some jobs where humor isn't a good idea. There's always exceptions to every bit of advice you'll hear, so have the good judgment to know when your workplace shouldn't involve humor.

One of the biggest rules with fun in the workplace is to avoid controversy when you're joking around on the job. It's stifling, but no one can deny that the current atmosphere of most businesses just isn't friendly towards controversial or racy humor. Stay away from joking about politics, race and religion, for starters.

Sex is another dangerous topic, though it may be easier to make jokes about sex without offending others, so long as you're aware of the exact definition of sexual harassment in your workplace and stay well within the lines of decency.

Never poke fun at other people within your organization, as you're trying to win friends among the people you work with, not alienate them. If you can't help yourself, be extremely careful with exceptions to the rules and be cautiously creative if you must have some fun with the topics you should avoid.

Poking fun at the very job you do or the industry you work in is a great way to earn some smiles from your coworkers and supervisors. While these types of workplace jokes may not be so funny at home or amongst friends, as they really don't understand the pressures or quirks of your employment, the people who are around you in your job will certainly appreciate humor about their frustrations and will be able to laugh over situations instead of grumbling.

One consideration for workplace comedy is choosing the right time and place to joke around. Naturally, the best time for some humor is when you're not working, but still around the people you work with, such as a coffee break, lunch, or during the commute. You can also try to be funny on the job, but when you're working, it's a good idea to use humor much more sparingly than you normally do. A tactful wisecrack now and then won't hurt your career, but if you don't show some professionalism and good taste, you're asking for trouble.

Start off adding humor to your workplace slowly, by trying out a few small jokes that you know are safe. All you really want to do is laugh a little and have the people around you smile as well. You'll feel more relaxed and the tension in the air will drop. You may even give your career a jump start, as people will want to be around you more often.