Psychologies Magazine 2018. Toxic People: Dealing with Dysfunctional Relationships by Tim Cantopher
1) Be assertive without being angry or aggressive (even if you feel that way). Quietly, but firmly, say what you need to say and, if you are challenged, focus on the substance of the objection, instead of any mud-slinging; toxic people may try to ridicule you or belittle you. Don't accept their judgements of you, focus on the point that you are making. Assertiveness is a skill and it takes practice. Observe people who are good at it and emulate them. Speak quietly and take your time.
2) Learn to set boundaries. Be clear about your limits and stick to them. When people are used to getting their way, they aren't happy if you say no. In setting restrictions, your responsibility is to yourself. If you don't respect your needs, others wont. When a 'boundary invader' is angry with you for standing firm, use a neutral response like: 'I'm sorry you're feeling angry with me'. That is different to, 'I'm sorry I made you feel angry'. You didn't make them angry. They chose to be angry. You set a limit and how they respond is up to them.
3) Take charge of your own choices and situation. If the toxic person in your life is firing off in all directions, you may feel you need to calm, placate or please them. Don't. Move away and focus on something more productive. Use a impartial parting comment such as: 'sorry you feel like that, but I've got to go, I'm running late.' You've taken control, minimised contact, not engaged in battle and not allowed yourself to be a victim.