I thought there was a chance that I could understand the instructions in this article, until I reached this point:

...begin by thread-tracing with a contrasting color the straight-grain line and the waistline cross-grain line on all of the garment’s major pieces...make sure you trace these grainlines on each piece. Always start a copying project by thread-tracing the straight-grain and cross-grain lines at the waistline on each major garment piece.

Whaa???