Common approach towards these questions is to simply state few adjectives about oneself like being dedicated and honest towards oneself and work.
Equally, stating weakness like nervousness, frustration and irritation will put you in thick soup. If you just throw these words out of your mouth in succession, the interviewer will be able to corner the candidate easily and this can turn out to be disastrous.
The right way to tackle these questions is to prepare oneself in advance. Start by jotting down your good and bad qualities. Then select the best one that you think is required for the position applied. Important tip here is whenever you quote strength or a weakness, it is imperative that it is supported by an instance or an achievement. This could be from your prior work experience which will be most relevant and valid illustration. If you do not have prior work experience then you can quote an instance from your college days that helped you achieve your grades in your assignments and perform overall successfully.
Talking about your strengths, make sure ample research is done in advance of what is required for the job profile. The general traits that interviewers look for are honesty, integrity, communications skills, confidence, team player, leadership and cultural fit. Other than the above, at least one job related strength example like sales and customer service skills depending on the requirement of the job should be exemplified. This will demonstrate what you have achieved in your prior job due to the particular quality and how it will be of assistance in your future job.
When discussing weakness, the common way is to address strength as your weakness. Example, “I am a perfectionist” These are too common and frequently used answers. Therefore, firstly the weakness which you state should not be among what your interviewer is looking for. Secondly, put across an actual limitation and present how you have overcome it or improved on it.
The best way to crack these questions is to be truthful at the same time explaining strengths and weakness in the most diplomatic way that it does not jeopardize your employment candidature.