set them, don't be open to relentless pushback
“A boundary is a limit or space between you and the other person"
"A clear place where you begin and the other person ends"
In life we are taught valuable lessons through our childhood, upbringing and social environment in our youngest forming years.
Don't ruffle feathers, don't be a bother, don't want to get on the wrong side of the person, fear of abandonment. These are all something learnt and sometimes the default due to trauma response.
However at some point in your life people will push your boundary so far back you no longer have one, and then you lose all safety nets. The relationship changes and you are the one that suffers.
There is nothing wrong with setting rules in any engagement in relationships, whether that is family, friendships, colleague's authority.
It is healthy to maintain some autonomy over interactions with others and what you are comfortable with. What is relevant and integral to you, without losing the freedom of that relationship.
Sometimes it can feel foreign scary or intimidating when first setting boundary's, but when you do set them, you will find that it make's life easier and more sure of what the rules of engagement are.
Setting a boundary really depends on what you are willing to settle for, what your expectations are, and how far you are willing to go (ie ending a connection) when those boundary's are threatened or crossed.
The easiest way to start is what are your non-negotiable's? Start there, and when you are more comfortable with that, you can set more, or add to some relationships to keep them professional/social distance.
Something to think about if you feel like you are getting pushed around or taken for granted.
If you have children or young person in your life, encouragement them to set them early, so it is part of all building relationship.