I came to this same conclusion about the middle of last year.. Now I write a contract for EVERYONE.. friend.. family.. doesn't matter..

I now require a 50% deposit to start, 25% at first fitting and 25% on delivery. so I put that policy on any estimate I send out, but usually by the time we get that far, it's a go! :)

Here, with exact details omitted, is the last contract I used..

Contract for Costume Design and Build

This agreement dated XX is between *designer* , (DBA *name of company* and hereafter referred to as Designer) and (hereafter referred to as Client), for costume design and build services for (name of project, hereafter referred to as Project) as follows:

Costume design and build labour @ *cost of labour or hourly rate*
Materials, notions, and wig not to exceed *budget agreed upon*

The costume consists of:
*everything you are providing as the finished costume.. from underwear to earrings*

To be paid as follows:
$1XX deposit (payment has been received)
$XX at delivery of costume
$XX due and payable *date due*
$XX due and payable *date due*

Payments are subject to a 10% late fee per 30 days past due.

Once the Client takes possession of the costume, no further alterations, changes, repairs, or any other design services will be provided by the Designer for this costume or project under this contract.

*any other possible information you think the person might need. A separate document for care of the costume is a good idea*
*sometimes I also put in a clause that I retain rights to the design (so I can build it again if I choose)

We the undersigned agree to the terms of the Contract as described above.



___________________________________________________ ____________________
Signature of Designer Date


___________________________________________________ ____________________
Signature of Client Date
*****************************************************************************************************************************************
Feel free to use this if you like. I wrote it myself; I haven't had an attorney check it, but it's worked really well so far!