It's time to do your makeup. It's kind of hard for me to tell you how to do yours because all the cats have different makeup patterns. I'll try to get patterns up at some point. Until then, you may need to figure out what colors to use and all that stuff. I can, however, give you tips.
I recommend, as long as you're not going to be sweating too much, that you use Snazzeroos Face Paint. You can probably get it at a local Dick Blick or at a costume shop. I've heard that it works really well. There is also one advantage to it that can also be a disadvantage. It washes off with water, althogh I recommend using soap when you wash it off. This makes it easy to take off. However, if you are going to be sweating a lot, or doing something near water, you could accidentally wash off all the makeup. My art teacher also has a recipe for some pretty good face paint that involves mixing tempera paint, baby oil, and baby lotion. I've used it before and it works pretty good, except that after a while it gets a little crusty. On Broadway, they use some stuff called "Bob Kelly" grease paint. I assume that it's sweat-proof. However, it's probably pretty pricey.
When you start your makeup, you're going to need to start with your base color. For some cats, you can just use regular skin-tone foundation. Others have white foundations. You might also find some with orangish or reddish foundations. You may have to figure out which one's best for you, at least until I get some patterns.
After you've got your foundation on, you can do things such as the eyes and muzzle. To do the eyes, your eyeliner will extend past the outer corner of each eye. The eyebrows will need to be drawn higher than your real eyebrows. The eyebrow usually have a nice exotic pattern to them. The queens will probably use brighter colors for everything between the eyelid and the eyebrow. For the mouth, the queens will most likely be wearing red or pink lipstick, although some wear brownish colors. For the toms, the lips are usually not accentuated much. For all the cats, the lip liner will go out past the lip and curl around, to create the look of a muzzle. Whisker dots will be added on the upper lip. The nose will most likely be painted black, although their may be a few exceptions.
Now comes the more difficult part: the detail work. You will need some good thin brushes. Most cats have little markings along their muzzle. Most will have little stripes along the side of their face. Add any details that you find necessary.
Once you are done with this, your face should be Jellicle-like and you should be done with your makeup.