One variety of human beings we tend to have too many of in our lives (too many as in, more than zero) is controlling people. Considering the stress they can create, knowing how to deal with controlling people effectively is serious business and it requires a key set of people skills.
Controlling People Explained
Fundamentally, controlling people have a powerful need to control others (doooh!). This need is reinforced by their belief (conscious or subconscious) that they can bend the will of other people to their own and use others to get their way.
Having lots of practice, most controlling people are real masters of pressuring and manipulating others. They often have very good people skills (the bad kind) and may initially come off as very charming.
The basis of beingable to deal with controlling people effectively, from my perspective, is making them understand that they cannot pull your strings. Thus, you are shaking one of their core beliefs and you have the best chances of them backing off.