The makeup starts with a full yellow base from the hairline to the chin. The Cowardly Lion is usually portrayed as a lighter yellow than the gold of your basic face-paint lion. Use a high-density sponge to cover the entire face, then go in separately for the eyelids and around the mouth. Afterwords, add shading with tan face paint to emphasize certain features, such as the nose and cheeks.
The jowls are a major part of the Cowardly Lion costume. If possible, they should be done with a partial mask to give them literal dimension on the face. Go over and blend the mask with face paint to match the rest of the face. This can also help in shaping the mouth, making a more feline triangle shape by coming down in two diagonal points from the nose. However, some versions choose to have the jowls extend only to the corners of the lips.
The only color on the lion's face should be a black nose and whiskers. Starting just under the nostrils, add black with a brush or small sponge up to just below the tip of the nose, then expand outward around the nostrils. This should create the illusion of an upside-down triangle. For whiskers, visit a party supply or costume store for long whiskers that can be glued on the upper lip and around the nostrils. If you choose, you can also just paint them on with an eyeliner pencil in thin, quick strokes.
The Cowardly Lion in the classic film had over-the-top raised eyebrows that were always pointed downward to better reflect his constant concern. Use fake eyebrows from a costume store or simply light brown makeup to give this facial expression to your lion. The eyebrows should start above the inside corner of the eye, about an inch above the nose. Then, they move up toward the hairline at a 45-degree angle. Adjust length and angle until they work for the face.
Once you've done facial makeup, the finishing touches make the costume. Add a flowing curly brown wig, complete with a rounded cat-ear headband. Clip the hair together around the chin for the look of a full mane that surrounds the face. A gifted stage mom or costume designer may be able to reproduce the effect with fabric if a wig is too much. For a dead giveaway, place a small red bow on the top of the head, or better yet, a crooked green "broken flower pot" crown.