In the book she instructs you to take a photo of yourself, and draw lines on it to determine your basic shape. This is harder than it seems. (And in case you think I'm exaggerating, the Ravelry forum is full of people posting photos of themselves and asking for help in determining their shape.) It's quite difficult to look at yourself properly, to not be distracted by your face, your hair, your oddly-shaped knees. Possibly it helps to do this over a few days. Eventually the oddness wears off and you can see that yes, that is you.
I took it a step further, and traced around the photo to make a line drawing of myself (to scale: 16,5cm high*). I printed out a ton of them, and started drawing different clothes on them.
Then I drew some dresses I've been thinking of sewing.
I even dove into my Pinterest boards and drew some of my favourite pinned outfits.
This might look like a lot of work, and very frivolous work too. But I'd rather spend an afternoon drawing next to the heater with a cup of tea, and a puppy asleep at my feet, than wandering through shopping malls, trying on clothes in badly-lit changing rooms, and coming home with nothing to show for my time. I'd rather spend a bit of time drawing than waste a whole day making a dress that, although fitted and of a gorgeous fabric, makes me feel clumsy and sloppy. Not to mention not having fabric to burn through, experimenting.
*Drawing to scale means that I can take measurements from the drawing and compare it to the schematic of a knitting pattern. I can also draw a schematic to scale, and overlay it on the drawing to get a sense of where things might need to be adjusted.