A couple of extra tips!
1. Chose a fabric that matches for jeans, the more heavy-duty your jeans the more heavy-duty your fabric should be.
2. More is ... more! So get a little extra fabric than what you need. (if you don't end up using is you'll have fabric for another project anyway!)
Enjoy your comfy jean skirts!
Oh! And this project can also be done with other kinds of pants and even shorts!