Lucky for me a local quilt shop has a monthly PPing club so I've done a few JN patterns. Our group leader is
very experienced with her patterns and she really emphasized following the cutting pattern as closely as possible. She also recommends reading the pattern carefully several times before starting a new project.
That being said, there are times when you just need to "wing it" Take a look at the cutting templates and compare them to the pieces they will be sewn in. There's usually a few where you can reduce your cutting to save on fabric. Also start cutting with the biggest/most important pieces in case you do have to do some creative cutting. I do recommend using the plastic bags for labeling and storing all the pieces...for me it does make a difference...ask me how I know!
All the prep work can be very time consuming but in the (for me) it makes the whole project go smoother and less confusing.
Couple other tips. Go to the Quitlworx web site to see if there are corrections to the patterns.
http://www.quiltworx.com/corrections/. Don't be afraid to ask questions here on the QB, and pictures can be really helpful. Lastly, if you are on Facebook, there is a Quiltworks group that has certified instructors that monitor the threads for questions, I've seen Judy and Judel post there.
Good luck and keep us posted on your progress!