Job interviewers know that people find it difficult to describe themselves, so more often than not it is the first question they ask potential candidates. However, it is actually a very plain and simple thing to do.
If someone asks you about yourself, the two things you need to keep in mind are to emphasize on your better qualities and gloss over the seemingly negative ones. While doing this you have to keep your head calm. Now, you will find that a different situation demands a different introduction.
In an Interview
A job interview is a necessarily formal meeting, and there is really no scope for you to jest here. You need to be firm and to the point. Highlight the positive aspects of your personality. No need to elaborate or even mention your negative points, as the interviewer is already adept at figuring them out himself/herself.
Think on what are the most salable points about you. If you can't figure, ask your friends or others who know you best to do it for you. One more thing, show a good amount of confidence in the interview, and have some evidence or a story backing up the positive points you list out about yourself and it becomes more believable.
A resume is your advertisement to all the companies you send it out to. Most people think that a resume is simply a list of all your achievements; however, it is so much more than that! Since, there isn't much scope for cross-questioning when it comes to a resume, you can exaggerate a bit! Once again you need to ask yourself, what are your best qualities.
The qualities that companies and their recruiters typically look for are hard work, creativity, leadership, good communication skills, and sound knowledge of the job profile. So, based on the qualities you see in yourself, you can describe yourself in a resume.
On a Dating Site
Now, obviously not too many people on a dating site are going to place too high a value on professional qualities, like problem-solving ability and leadership skills. Describing yourself on a dating site is a totally different case. Think of all your socially acceptable qualities now.
You can give a great demonstration of your humor on the 'how would you describe yourself' section on a dating site. Try to be witty and it'll be well-appreciated.
Simple Examples of Self-description
When you're writing your introduction on a dating site and on a resume, it is going to be decidedly difficult. So, if it still hasn't helped you learn how to describe yourself, you could use one of these ways mentioned to do so.
For a Resume/Job Interview:
My academic records show, I am hard-working and loyal. I am also versatile and love to handle challenges that life throws at me. A successful team leader and team player in my previous company. Worked for (number) years now, I believe I'm well-versed with the different procedures this profile involves, and so I can be a great addition to your organization.
For a Dating Site:
Fun loving and intelligent young man/woman looking for a date. Big surprise isn't it!
As you can see, the question is not too difficult to answer. After all, you know yourself, your qualities, and fall points best! So, just write them all down and frame a few fancy statements around them! Good luck!