I have taken apart an item like my favorite jeans or shorts and step by step have written down what I have riped and mark the pieces with coordinating #'s as to what I wrote on the paper. After doing all the steps and having everything apart I use the pieces as pattern pieces to cut out. Starting backwards I sew the garment together and what a reward. I have done this on my items that are just so worn you can't wear them anymore and by doing that you have a whole new garment. It is great! Try it! You may just do more!

I found a book by Mary McCarthy called "Copy It! Duplicate Your Favortite Clothes," and reading it now. The 2009 edition includes pants and skirts too. You can make your own pattern WITHOUT taking the clothes apart!
Can't wait to try it.
BlueBars

Here is a link that might be useful: http://www.marymccarthysews.com/