Budget
The first thing to think about when starting on any project is how much
money you can afford to put towards your creation. If your
budget is rather tight, your best bet is to plan extensively so you don't have
to re-do a botched attempt, and decide which pieces matter the most to you to
spend money on. A good estimate for a costume is around $100, more or less
depending on time, effort, and quality of supplies.
Resources
It's hard to start something if you don't know where to buy what you need.
Make a list of places, or a folder in your bookmarks/favorites menu, of stores
that carry costume supplies. Search engines, the yellow pages, and references
from people of experience are good sources of information. If you haven't
already, browse my list of Useful Links.
Obstacles
Sometimes it's money, sometime it's Parents, sometimes it's geographical
location (costumers in the UK tend to have it rough finding supplies, but that
doesn't mean UK kitties should give up hope!). If your
main obstacle is that you're broke, first plan out your costume entirely and
list the cost and supplies that you'll need. Once you have a goal written down,
try to figure out ways of earning money. Experiment with costume techniques
using materials you might already have, draw pictures of your dream costume,
etc.
If it's your parents giving you a hard time about undertaking a project like this ("Why would you want to spent $100 on making a costume? Halloween isn't for six months!"), the most important thing is not to have a tantrum. You want to appear mature and intelligent. Try to find out what specifically they dislike about your choice of hobby; do they think you will neglect homework or chores in favor of working on your costume? Do they think you're "too old" for Halloween? Hang in there, many beginning costumers have these same obstacles. Try to work out a solution with your parents, especially if you're hoping that they'll help fund your efforts. If your parents won't let you purchase supplies over the internet, use your phonebook to locate sources.
Geographical location is a tough one. If there are *no* local sources for needed supplies, you may end up paying a lot for shipping by buying things over the internet. If you live outside of the United States, finding supplies is usually a lot harder (particularly Aunt Lydia's Craft and Rug yarn, and Floral spray). Sometimes shipping costs can be reduced by having a friend in the states buy and ship supplies to you rather than going straight through the company. Check out the shipping costs before deciding where to buy.
Where there's a will, there's a way, so don't give up no matter what the obstacle!
The "look"
Once you're ready to start designing your costume, experiment with different
styles to see what suits you best. Image galleries with pictures from
productions of CATS from around the world are a good place to get style ideas,
as well as Marzi's collection of pictures of fan-made costumes. Even if you're
not a talented artist, making lots of concept sketches can help you decide what
you want your costume to look like. If you can't think of anything, there are
lots of budding costume designers in the online costume community who would
probably jump at the opportunity of designing a costume just for you!
Time and Effort
Cold hard fact: To own a fantastic looking CATS costume, you need at least
one of the following: Time, Effort, Skill, or Money. If you have the first
three, you can usually get around the third, and if you have a lot of $$$ you
can pay someone else to do the hard work for you (but don't count on it as an
absolute). Consider the amount of time
and effort you will be able to devote to this project when making decisions with
regards to method. Decide which of the four areas you lack the most in, and work
around them. For example, if you have a deadline you might decide to pay someone
else to make parts of your costume while you make the others, cutting the work
time in half; or you may decide to use a speedier method that might compromise
quality.
Skills
Replicating or inventing your own CATS costume is a project that requires
some indispensable skills. Knitting, sewing, and painting are some of the
basics. If your confidence with regards to your artistic skills are low, don't
be too discouraged. With time and practice, your skills will improve.