April starts with April Fools Day, an apt time to think about all the foolish things we do to sabotage our careers and how to avoid doing these dumb things in the future.

Here are the top 10 dumb things people do that you should avoid:

1. Putting everything on your résumé. Your résumé is not supposed to be your life story. It is a sales tool to get you an interview with a potential employer. Put just the relevant jobs and education. Employers are most interested in your skills and accomplishments. Don't hide those in giant paragraphs of text. Be specific.

2. Inflating your résumé or lying on your résumé. Be honest. You can get fired for claiming untruths. If you don't have a degree in computer science, don't say you do.

3. Putting unreleased footage on a demo reel. If you have worked on a film or project that is not yet available to the public, do not include it on a demo reel that you mail to a potential employer. Instead, send the demo reel that got you the great job in the first place. If it's good enough for your current employer, it will probably be good enough for your second one. You can mention your work on the unreleased project in a cover letter and on your résumé. Your discretion in not including it on your reel reflects good judgment. If you get an interview and the potential employer requests seeing some of the unreleased footage and you have it in your possession, you can bring it with you and screen it at your interview. But you must keep an eye on it at all times and it must not be left with the interviewer.

4. Putting another person's work in your portfolio or on your demo reel and claiming that it is yours can backfire badly. The industry is very small and putting someone else's work in your portfolio is a lousy idea. You might interview with someone who actually worked on the project, or know the person who did the work you are claiming to have created. This has happened — Bob Kurtz, a well-known animator and director once got a call from another industry pro who told him that an artist was claiming work that looked liked Bob's. When the interviewer asked Bob if the artist had ever worked for him, Bob said that he hadn't had the pleasure of making his acquaintance. Needless to say, the artist did not get the job, and had a hard time getting work anywhere.

5. Speaking ill of someone you worked for or with. This may be tempting, especially if the person was really difficult to work with. Even if the person interviewing you invites you to badmouth the employer with leading questions, don't criticize your former employer. Never say anything remotely negative about the company or people for whom you've worked.

Once you have the job, here are some things people do to sabotage their careers.

6. Being negative, complaining and harboring a bad attitude. Po Chu-i, an ancient Chinese poet observed, "The man you never see laughing — he's a fool for sure.” If you aren't excited about your work, it might be a sign that you need to explore other opportunities. Cultivate your sense of humor and maintain an upbeat attitude. People like to work with optimists, and those who are open to new ideas and perspectives.

7. Failing to deliver work. A sure way to shorten your career is by failing to deliver work when promised. All freelancers know that the key to success is delivering work on time or before the deadline. If you realize you are not going to be able to complete the assignment on time, contact your employer and let them know in advance. No one will be happy that you missed a deadline, but a client will be furious if he finds out when it's too late to do anything about it. It's far better to ask for help than to simply not show up or be late with the work. If you are working in-house or on staff, give your supervisor a heads-up if you need help in completing your work on time.

8. Fooling around. Distracting others when they are trying to work is a sure way to get noticed for all the wrong reasons. Minimize your time at the water cooler, or on breaks, or visiting in someone else's cubicle (unless you are working on a project together and are getting or giving feedback or having a meeting).