Step 1 - Start your drawing with an "L" shape for the right eye and a "J" shape for the left, close each shape with half a circle.
Step 2 - Add a big circle inside each eyes.
Step 3 - Draw another smaller circle inside the one we added before with a small circle at the top.
Step 4 - Add two curved lines under the eyes, draw a small line for the nose and a big smile for the mouth.
Step 5 - Draw the shape of Dory's cute face, start with a curved line above the left eye and draw a square shape in the middle, connect it with a symmetrical line from the right eye. Draw the bottom part of the face using the same technique.
Step 6 - Draw a fin on each side of Dory's face with 2 lines inside.
Step 7 - Draw the tail on the left side, start with a curved line just under her eye until the middle of the fin.
Step 8 - For the coloring part, you can add shading to your drawing above and under the eyes, around the mouth and use lighter blue between the eyes and above her eyebrows.