Judy James, a body language specialist and author, says that most interviewees who ask for advice are told 'Just be yourself!' This, she says, is the wrong approach. 'If you are just going to be yourself, why not turn up in an old tracksuit? You would never do that, so why just 'be yourself' in body language? Instead, by marketing your body language, you can control your own success.'

According to experts, body language accounts for 55 per cent of the effect we have while communicating. Tone of voice accounts for 33 per cent and words for just 7 per cent - so how you behave matters much more than what you say.

Employers nowadays are cautious about the fast-talking interviewee who has learned certain words and phrases but who may be hiding a basic lack of knowledge or simply lying. So they look increasingly for other signs which will show a person's character and ability- such as body language.

You will be more impressive at an interview if you have prepared by doing a 'dress rehearsals' of your facial expressions and hand movements in front of a mirror. It sounds ridiculous but it works. When it comes to facial signals, you should always smile when you enter the interview room and when the interview finishes, because first and last impressions count. Try to smile by the eyes first- if models can do this, so can we. There is nothing worse than a painted-on smile and terrified eyes.

You should also try to maintain eye-contact with the interviewer, but not for too long. If you are in front of a panel of interviewers, look first at the person who has asked you a question, and then at each of the other panel members in turn. Looking just at the questioner is a common mistake.

Your hands should generally stay loosely in your lap once you are sitting down. Use them to make a point occasionally but never raise them above shoulder level, and do not play with your hair, watch scrap or jewellery.

Tell-tale signs that the interview has gone well are: increased eye-contact, the repetition of your name and perhaps even some closer body space. A look of relief may also be a giveaway sign- the process of choosing a candidate is stressful for interviewers, too.

If you haven't been impressive, the interviewer will be trying to not behave in a familiar fashion. Negative tell-tale signs are avoiding eye-contact and a parting handshake which is firmer than the one which you were greeted with.

Body language is a subject that we have all heard about, yet we are not aware of the effect that our own body language has on others. In fact, it is vital- and after someone has noticed it for the first time, even subconsciously, they are unlikely to change their opinion because of what you say. So, take the trouble to get it right at an interview.