After you have drawn your pattern in accordance with the instructions given in the book, you will have a couple of outlines on your graph paper. One will be the back and one the front of your trousers. (NB you have 2 overlapping outlines, because the pattern for the back and the front use the same points to measure from - there are just slight differences.) It's helpful to draw the front pattern in a colour such as red, and the back in green for example.
The next stage is to trace over each of those outlines with tracing paper, so that you have 2 pattern pieces which you can then cut out and use on your calico. This is where the 2 colours really helps you to see the outline through the tracing paper! Don't forget to add darts and straight grain marks.
Do not cut out the paper pattern yet! You will need to add a seam allowance to the outline. I use a French Curve ruler to help and chose 5/8" so that I had some wriggle room if the trousers needed letting out.
On to cutting out, and stitching a toile for fitting.
You can see that they do fit around the top, but are waaaay too big on the legs, and need slimming down. Not so much Italian chic, more ferret catchers work wear!!
It's very hard to fit these on your own so I found an old pair of trousers that I liked the leg width of, and measured the new against the old. Wow! Just need to do some alterations to the toile and try on again.
Once I've altered the toile and am happy I can transfer the alterations to the pattern pieces for future use.