When you have project instructions but no pattern
I am new at sewing and am currently reading the book "100 Ways to Use Your First Sewing Machine." My friend and I attempted to make the tote bag in the book - however, there was no pattern for the bag, only instructions (i.e. cut four panels of 15 x 17 fabric). The tote is not yet finished, but it's not exactly coming along as planned - I think that the cut is off.
How do you make a project for which you don't have a pattern?
I measured the 15 x 17 on the fabric, cut it to create the first panel, and then pinned it to the fabric as a template to create the other three panels. However, I don't think that this was the best method, since the pieces are not all the same size and the cut was shaky.