How to Draw Ariel
To draw Ariel, start by drawing her head and face, including 2 big eyes with thick eyelashes, smiling lips, and a small nose. Then, draw her signature red hair, making it long and voluminous. Next, draw Ariel's upper body and arms, followed by her long, curved tail. At the end of her tail, draw 2 tail fins that make a "V." Finally, draw the seashells on Ariel's upper body, and erase any unnecessary lines before coloring in your drawing.
Sketch Ariel's wireframe. There are three shapes common to her design: her head, torso, and waist. She has a fairly oval face, with prominent cheeks, a rounded forehead, and a dainty, yet pointed, chin. The three shapes need to be in proportion to each other and all line up at the correct angles. When you're drawing Ariel, what is she doing? If she has fins, she's probably swimming! Sketch the additional shapes needed for her torso, arms and tail. Include lines on her face to line up her eyes and nose, placement for her seashell bra, her elbow and shoulder joints, and fins. Sketch Ariel's figure and add her unique design traits. The most important being her unique hairstyle, of course! Remember: She's in water, so her hair doesn't need to be along her back and her fins are floating, too. Ariel has wide, Disney princess eyes (they're all relatively similar). They're usually open and curious-looking. Her nose is dainty and small; her lips are generally in a bit of a smile. Her hair miraculously has no part and is incredibly voluminous. Her hands and arms are generally held strong but femininely, like a ballerina. She has definite poise (especially for such a youngster!). Refine the sketch using a smaller tipped drawing tool. You want fine, definite lines that are determined and confident. If worst comes to worst, just resharpen your pencil. Draw the outline over the refined sketch. If you have anything to add or change, do it now! The outline is your last round of actual drawing. Did you remember the lines in her fins, top, and waist-frills? Erase and remove the sketch marks. That's it for drawing! Are you feeling ambitious and going to tackle Flounder and Sebastian, too, or just keep it to Ariel? Add color. To keep it traditional, her seashell top should be purple, her tail should be medium green, and her fins light green. But this is your drawing -- maybe she should be sporting zebra stripes? Sketch Ariel's wireframe and pose using the same technique as the previous method. Just remember that as a human, she actually has to be using surfaces! The angle of her body needs to be believable. Sketch the additional shapes needed for her torso, arms and legs. If she's sitting, what is she sitting on? What is she looking at? Try to always maintain a curve in her torso, through to her waist. Don't forget her facial lines and joints. Her large eyes should match up with her small nose and smile. And her hands and fingers need to be delicately proportioned, too. Sketch Ariel's figure and add her unique design traits. You may need a template, as Ariel in her human form is much less iconic than when she's in her fins. The dress is fairly basic -- full, straight angles, and complemented by an absolutely huge bow. Have you mastered her hair flap yet? The great thing about it is that it doesn't have to look believable at all (she's too perfect to be human). It just has to look adequately Ariel-esque. Refine the sketch using a smaller tipped drawing tool. This is the chance you get to put the delicate lines exactly where you want them. The finer the tool, the more precise you can get. Draw the outline over the refined sketch. It'll be a lot easier to do this if you've refined the sketch. Sometimes too many lines gets a bit confusing. Outline whatever lines need to be present in your final draft. Have you got the wrinkles in her fabric outlined? The lines in her hair? Eyelashes? Don't forget those eyelashes! Erase and remove the sketch marks. Be diligent; depending on your medium of color, pencil marks (or even eraser marks) will sometimes be visible. Add color. The bodice of her dress should be dark blue, her skirt and bow medium blue, and her sleeves light blue. Her eyes are also blue and her hair is that classic fire engine red. Draw a circle. Put a curved line underneath for the basic shape of her chin. This will be her head. Draw in guidelines for the facial features (i.e., where her eyes, nose and mouth will be). Ariel has a very rounded forehead, curved cheeks, and small chin. Though this may look funny initially, it's correct. Detail her face. Draw two curved lines for the brows that are up, happy, and a bit inquisitive. Add in two big eyes and draw thick eyelashes as shown. Draw a small nose and full, smiling lips. Add a half circle for each ear (if drawing both). The majority of her eyes should be taken up by her pupils and irises. Think in terms of rounded triangles. Sketch her hair. Remember, Ariel's wavy, luminescent red hair is her trademark, so emphasize it as much as you can. It should go at least down the length of her back, ending in a soft curve. Don't ask how the flap works -- it just does. And it seems to be floating off of her forehead. Don't worry about abiding by the laws of physics when it comes to drawing this princess! Work in a few lines for her hair layering and all will be well. Add shapes for the body. Draw a small rectangle for the neck and a square for the torso. Add circles for her seashells, and a small circle underneath that for her waist. Put a larger one below that as the beginning of her tail. Ariel (the water version, at least) always has a slight curve to her body. It should resemble a very loose "S." The placement of the shapes should mirror this angle. Add in her arms. Draw two ovals connected by a circle. Draw small ovals for the hands and thin shapes for the fingers. Ariel's fingers and hands are especially delicate and pretty, so be careful with this part. Remember, Ariel holds herself like a dancer. Her arms are strong but free, and her fingers hang gracefully. Draw curved lines on either side of her torso. Try to have them gently arcing into smooth lines, converging at the end of a length about the size of the rest of her body. These lines will serve as the tail. Add tail fins as shown. They should fan out gracefully from the end of the tail, creating an inverted "V" shape within them. Draw lines inside the tail fins to make them look more like real fins. Sketch in Ariel's seashells and the fins at her stomach. These fins are comprised of a round, ruffle-like shape at the top of her hips. It is where the tail begins, so don't make it too high. Add details and outline the entire drawing. Erase any unnecessary guidelines. Color her in using violet for her seashells, green for her tail, and (of course) bright red for her hair. 
Sketch Ariel's wireframe. Sketch the additional shapes needed for her torso, arms and tail. Sketch Ariel's figure and add her unique design traits. Refine the sketch using a smaller tipped drawing tool. Draw the outline over the refined sketch. Erase and remove the sketch marks. Add color. Sketch Ariel's wireframe and pose using the same technique as the previous method. Sketch the additional shapes needed for her torso, arms and legs. Sketch Ariel's figure and add her unique design traits. Refine the sketch using a smaller tipped drawing tool. Draw the outline over the refined sketch. Erase and remove the sketch marks. Add color. Draw a circle. Detail her face. Sketch her hair. Add shapes for the body. Add in her arms. Draw curved lines on either side of her torso. Add tail fins as shown. Sketch in Ariel's seashells and the fins at her stomach. Add details and outline the entire drawing. 