Toxic people are among us, often living their own personal dramas. They may not be recognizable at first glance, but when you sit down and talk to them, you will probably know.
They are the ones who will see a black spot on your "white" and will emphasise it to you, literally "sucking" all your positive energy and self-esteem. The best option would be to remove these negative people from your life, but what happens when during a social gathering or family meeting you have to sit at the same table with them and protect your energy?
For these short-term situations, an easy method you can apply is the method of the "Grey Rock". Psychologist Nandin van der Linden, through her blog, claims that the "Grey Rock" is a tool that prevents toxic people from escalating the situation, riling you up and stressing you out—three things they absolutely love to do.

In this way the toxic person is discouraged from manipulating you, which is their main goal. How is it done? During every interaction with the toxic person, speak in a neutral voice, talk about boring subjects, don’t make eye contact and give short, generic answers.
Do not tell them about your promotion, the new clothes you got or the surgery your father did. When the issues are general, the toxic person does not live his/her drama and has nothing to comment on to make you feel miserable.
What you need to be careful about, is to never be rude to the toxic person. Depending on your personality, transformation into "Grey Stone" is not always easy but once you get the hang of it, it’s an extremely effective way to protect your time and energy and subtlety is the key.
Warning: As explained above, this method is good to use only for short-term situations. For long-term, respect yourself and remove that person from your life, or at least have minimum contact with them (in case of being part of family or work environment). The reason is that essentially every time you will use this method you will suppress a part of you, in order to protect your energy, hence by doing this with someone that is close to you it can negative effects in the long-term.