Designing you own character can be lots of fun, but It can also be bit harder since you don't have pictures to look off of. There are lots of things that you have to consider when making up a character. Yet at the same time, It can also be better since you don't have to follow a pattern.

Coming up With a Character:

first, you have to get an idea. you will have to consider the age, gender, personality, etc. of this cat. Some where to start would be if you have an online character, you can create what you want that cat to look like (I did that). Maybe, this is what your real cat looks/acts like. there are a million possibilities.

Wig:
if you cat is an adult the wig is usually larger. if your made up Cat is young, you would want a smaller, simpler wig. also, the wig should match the cats colourings and patterns. plus, is there any special featuers on this wig? Like, Jenny has round ears, and the back of skimbles wig is sometimes slicked back.

Unitard:
First, do you want a mock turtleneck, or if you want a boatneck? Then you should think of markings. If you want to look taller/slimmer, vertical stripes are helpful. but if you want to look shorter/wider go with horizontal stripes. then, is your cat male or female? felmales usually (not all the time) have white bibs,brighter color, and have more of a pattern to the unitards.
Tail:
how long do you want your tail? the kittens usually have shorter tails. then, how thick (fluffy) do you want you tail? If you cat is an alley cat, then it should be thin and scraggly, whereas the house cats have fuller, fluffyer tails. and, do you want a pattern on your tail (one layer white, the next black, then yellow, then back to white, and black, and yellow...) or do you want all the colors thrown together?

Warmers/Gloves:
now you have to think of the length of your warmers. The kittens and younger cats usually have longer warmers (i know munku has long warmers! I said usually!!!) and do you want really fuzzy warmers? now, for arm warmers. is your  cat male or female? the males (excluding Misto and tugger) all have warmers on thier arms. now, the some of the queens have gloves which brings us back to the whole length thing again. Jemima is the only kitten who has gloves, but yours can too if you want. also, you will want the markings on your warmers to match the rest of your costume.

make up:

this is hard to figure out (at least for me) there is a base color, then (unless you want a solid colour, which is kinda boring) then with markings matching your patterns. you should know the tom/queen thing with the mouth, and if not, go to the make up section on this page. you can pretty much do whatever you want with the make up.

collar:
is you cat a house cat or an alley cat? if its a house cat- have a collar, if not- don't have a collar. simple, unless its a runaway >^_^<  your collar can be plain, it can have spikes, jems, or anything you want. heck, for fun, stick on some old dog tags! also, what colour is your collar? they are usually black (Victorias is white) but hey- its your cat, have red, green or whatever colour you want! and, I think what is on this page, is all I can do in one sitting!