This article is written for knits, but will work just as well for crocheted clothing.
http://danceswithwool.wordpress.com/2008/02/12/knitting-tips-how-to-knit... [1]
Links:
[1] http://danceswithwool.wordpress.com/2008/02/12/knitting-tips-how-to-knit-garments-that-really-fit/