Rule of thumb: Never lie. It's bad karma. It will back fire. It will be found out. Just don't do it.
But every rule has exceptions.
Small white lies can be a social lubricant.
A little white lie is a little white lie when the distance between the truth and the little white lie is small and the lie is believable by the other side and by you.
Warning! Small white lies should be used with care.
Example:
When asked "does this dress looks good on me" by definition you need to use a little white lie, whatever you think should be augmented a little. If the dress looks O.K. the answer should be something like "It looks very good on you.". If you will answer will be something like "It is the best dress you ever had on you!" you will be caught.
You can always try and guess what the other side wants to hear and give an answer that is a compromise between that and what you really wanted to answer.
