Summarize:

A mime is instantly identifiable by their signature makeup. A white base for the face is traditional for mimes. Find a white “grease” or paint and apply it all over your face with a sponge or brush. Your natural skin tone should not show through the white makeup when you are done.  Be sure not to get to white makeup in your eyes. You might also try small circles of light pink blush for a happy or girlish mime. After you’ve applied the white base, apply thick black eyeliner all around your eyes. Then, go over your natural eyebrows with black paint. You can also add stylized "tears" running to the middle of the cheekbones. Finish with black or dark red lipstick. Keep in mind that you can alter the makeup to your character and preference. Serious mimes might not wear the classic "costume" anymore, but you can wear this costume as a beginner. Find a black-and-white horizontally striped shirt—ideally with a boat neck and three-quarter sleeves. Wear dark pants, black suspenders, white wrist-length gloves, and a black bowler hat to complete the look. You can also wear a black or red beret.  This outfit and make-up has been a tradition of many famous mime artists, including the legendary Marcel Marceau. You do not need to dress this way. In fact, it is considered a cliché by modern mime artists. If you wish to create a character, adopt a mood with your clothing, makeup, and lighting. For instance, you may wish to highlight the plight of the homeless sleeping out in the cold during winter. Paint on a sad face, wear tattered clothing, and use dim lighting. Think through a story that allows you to mime trudging despair as the homeless person seeks shelter for the night.
Apply the white base. Add the dark makeup. Wear the traditional black and white striped mime costume. Choose a costume for your character.