"We all need to stand on our own two feet without stepping on other people's
toes."
When you have to fight for your own rights, protect the other's too. Rather than a
"one wins and the other loses" handling of situations, look for ways that both
sides can benefit or win something in the end, so that they won't feel a need to want to
get even with you. Because egos always get even.
Use horse-trading. If you try to stay sensitive to the other person's needs, you can
almost always find a solution where both sides get something that doesn't require either
side to have to feel that they're being the loser. Think of some things you can do for
them in return for what you want. For example, a way to soften it when you're refusing
someone's request is to offer an alternative for solving their problem. Or try to look for
ways where one gains something in the short run and the other in long term.
The stronger your stance needs to be, the more important it is to try to soften your style
-- to make your stance more palatable.