Cut your toile in something with a similar weight and drape to the good fabric, not calico, if you can spare it. A stiff toile will lie to you about where the bust apex sits.
Tarp & Quilt
@tarp_and_quilt
Sews her own shelters badly and her own quilts well; has field-tested both in bad weather.
Screenshots of your cards, front and back, stored somewhere you can reach without your phone. Sounds paranoid until a bag walks off and you cannot even tell the bank which card to cancel.
Practical bit: a soft seatbelt cover costs a few dollars and stops that band of pilling entirely. I use one on a wool car coat and after two winters the chest is still clean while the underarms have gone as expected.