Plot points are simply moments in your story that are life changing. Not for the author, but for the protagonist. I have often times heard it as moments that take your story in a new direction, but I believe it is more than that. Consider a story where the protagonist moves to a new city and gets a job. While that is a life changing event, it is not going keep the interest of your audience as this is a common occurrence. When making your plot points more intense than reality captures the audience's attention. To make a move more intense, you could move her into a home with an old man that hates women, and he is not afraid to let her know that at every possible moment. Or perhaps you could focus on work. Imagine your farm boy finds out that the fabulous job offer was nothing more than a con and he is now penniless in a strange city where he doesn't know the language. Either choice will keep your audience because now the protagonist has just had a life changing event that leaves him or her with a dilemma.
Demented elves believe that each plot point should bring more pressure than the last. Think for a moment and turn up the heat. That is what makes the story more interesting. It is all well and good that the heroine has to learn to live with someone that hates her, but then what? After a while, it gets old. So know that the story needs a new direction, what if the old man gets kidnapped? What if the heroine is the only one the kidnappers will talk to? Now we have a new direction with a new dilemma. One that will force the protagonist to make an even more difficult choice. The more demented the plot point, the more the audience will be interested in the story.
The three act structure has three. Each one should be more demented than the next. Each one should present the protagonist with a life changing dilemma. They do not have to be unbelievable, unreasonable, or involving fictitious creatures, but they do have to be extraordinary. When thinking out your plot points make them as interesting as possible.