TRSE: How To Draw Tutorials:
Emotions:

    The emotions especially comedic/exaggerated ones shown in many Animangas may be what helped Animangas become so popular. Yet, the emotions are quite hard to master, because it required a good understanding of how the emotions work in response to various situations. It's also very true for any movie actors and voice actors who have to display correct emotions when acting. Because of our different personalities, we can produce so many different & complex types of emotions based on various situations we face. We can be angry at something, and be angry in a different way at something different. The personalities of the characters can shape the way they display their emotions, and the artists tend to have different ways of drawing the emotions even similar ones.
     Because of varying artist's preferences/styles, people's personalities, and ways of reacting to varying situations, it is very difficult to teach anyone how to draw proper emotions, but it's possible to go with the basic emotions. In many cases, the emotions are not something that can be done logically, and they has to be done in a way the actors display their emotions during the movies as if they were actual characters of that movie. Many cartoonists have the mirrors that they use to draw the emotions displayed on their faces, or they just feel the tensions in their faces when they make any emotions. It's just a matter of understanding how the muscles work in the face, and how they act in response to emotion invoking situations. The best way is make the emotions work to pretend to be that character you're drawing, and act out that character. Let's say that you're very happy with a gift you got. To draw a happy emotion on your face, all you do is pretend is that you got happy when you got a gift. When you're happy, "freeze" your emotion and feel where the muscles are most tense (like raised cheeks for example). You can use the mirror to observe what's on your face when you're happy. You draw the happy face based on what you felt on your face or what you saw in the mirror, and if you want, you can exaggerate those emotions to make them seem more dramatic or comedic. That's how I learned to produce my own emotions based on Japanimation. Sometimes, a combination of two or more emotions can result in a different expression.

    Let's look over the basic examples of various emotions displayed below, and many pictures here are taken from my own BSSailorMoon fanfic mangas (much easier than spending a lot of time searching thru internet for hard-to-find screenshots). It's possible to get better at drawing emotions as you get more experienced with drawing.

Relaxed:
Neptune was making a comment in relaxed tone. 

    When the characters are relaxed, their faces are just straight (no muscle tensions in face), hence, no emotions displayed. Varying the relaxed faces can show off their personalities. For example, Uranus would frown a bit even when she's relaxed.
 

Happy, Cheerful, Excitation
Pluto displays a faint smile.

   That is a basic smile which we feel muscle tensions tagging only at the ends of the mouth.
 

Venus cheerfully makes a point/suggestion.

   That face is more lit up. The eyes tend to be closed in upside down 'U' which can vary in height while the eyebrows are raised slightly (muscle tensions). More cheerfully/happy, taller the upside down 'U' can get. There are times when the eyes can stay open while being cheerful.
 

Jupiter's having a daydream.

   You can tell by her dreamy face that she's having a good daydream. The eyelids are lowered as if looking sleepy, with a smile on her face. "Sharing toward nothing" can indict that a person is daydreaming too.
 

Venus's chuckling devilishly as if she pulled a trick on someone.

   The cheeks are pushed upward when grinning like that, resulting in the crescent shaped eyes. A happy face can can have those crescent shaped eyes, but with a broad smile/open mouth instead of grin.