Be very careful when cutting blue jeans. It can put enough stress on your hands to induce damage (in my case, arthritis).
I have an electric scissors for cutting apart blue jeans, and I highly recommend them. Mine are very old and I haven't researched new ones, but this is similar in looks to what I have:
http://www.amazon.com/SKIL-2352-01-3...dp/B001B64ZEE/
The electric scissors make cutting the blue jeans apart ***enormously*** easier! You still have to subcut with a rotary cutter to get the shapes you want (an electric scissors is probably not accurate enough for this; I know mine is not), but at least your hands will be in better shape for that. Aside from making the job a lot easier, the electric scissors is also much faster than using a scissors or rotary cutter for getting the flat pieces.