Step 15: Draw the rest of the unicorn's head using the initial shapes and lines as guides. Follow the basic path of the guides as you darken the lines and add a curved line on the bottom for the jaw. Add a few lines within the head for the protruding veins.
Step 16: Use the line on the head as a guide to draw the unicorn's horn. Make the horn thick at the base and pointy at the top. Add some lines inside for a spiral effect. You can skip this step for a regular horse.
Step 17: Use the initial lines as guides to draw the legs that are on this side of the unicorn's body first. Lightly sketch the shape of the leg as you follow the basic path of the guide. When you get the structure of the leg right, darken the lines. Pay attention to how the leg bends. Add a thicker square-like shape at the tip for the hoof. Pay attention to how the leg bends. Draw the hind leg on this side of the body the same way. Lightly sketch the shape of the leg first as you follow the path of the guide. Darken the lines when you get the structure of the hind leg right and add the hoof shape at the bottom.
Step 18: Use the other lines as guides to draw the unicorn's legs that are on the other side of the body. Remember to sketch lightly at first and only darken the lines when you get the structure right. The shape of this leg is similar to the other front leg but placed a little higher. Now draw the hind leg on the other side using the same technique. The base or top of the legs should be a little thicker than the base of the front legs.
Step 19: Draw the unicorn's mane along the left side of the neck using a series of curved lines. Try not to draw every individual hair strand. Instead, draw the mane as a single shape. The shape of the mane is compost of many curved lines that come to a point, like wavy spikes. You can make the mane longer or shorter if you'd like.