Our usual tools
Our basic structure of a face. A smiling face has some little difference in our structure. But don't worry, they are really simples.
One difference you can find it in the eyes, you'll see, when we smile we contract 15 facial muscles that affect the basic structure of the face. You can see the difference between them.
Well, we have finish the eyes. Don't worry about this, this is just an sketch and is not the important part. We have to focus in the smile.
To measure the width of our smile we use as a reference the outer edge of the pupil (the edge that look to the inside of the face)
To draw an smile, you have to start drawing the inner of the smile or the inner edges of the lips. Began with the one that forms the upper lip.
Then go with the other lip. An important thing: this smile is like a little smile, only shows the first line of the upper teeth. Why? Because is more easier, the problem with the smiles are the teeth.
Now we have to draw the upper lip. This's going according how do you want your mouth form, usually the upper lip is more thin that the one below. Remember this is an sketch.
Okay, we have the other lip.In a smile you will have to do constants changes because is not really an easy thing.The best thing to see mistakes is to see the draw in front of a mirror o taking a photo
It's truly necessary make this ugly lines, don't worry, we'll erase them later.
Okay, now the difficult part: the teeth. Draw a line in the middle of the smile, this is going to be our reference.
Draw all the other teeth. But don't let you be fooled! This seems to be an easy thing, but believe me, you'll need to re do it a few times.
Okay now we are going to banish that ugly lines, erase softly both ones. With the pencil, softly, mark the lines near the mouth and then blur them with your finger.
We need to make the shadows, so make them with a pencil as you can see in the left of the mouth, then blur them until they look like the corner of the right. Paint the upper lip truly dark.
Okay, with the finger now we have to make the shadow bellow the nose.
We really need a pencil very sharp for this step. We have to make the shadow of the teeth, that hides in the lip that is below.
Then, carefully and very softly, make the gums. Maybe you will need to darken the upper lip.
For the lip that it's below, I have blur the edges and start to make the shadows an the light. Is really necessary to make shadows and points of light to the lips because then they look more natural
It's possible that you will need to fix some details in the smile, but it's normal. Mark the bridge of the nose, erase the lines and now we can make the shadows and the light of the face.
So that's it! Feel free to ask question and suggest new things to draw!