When working in the garment industry we would use clear cellophane wrap (the type used to wrap gift baskets) to trace off a pattern from a garment when we wanted to copy it. Using a sharpie, you would trace around the garment one section at a time -then label it . This is part of "knocking off" a garment. I still use this great technique as a starting point. I transfer the pattern to gridded patternmaking paper and add seam allowances along with any alterations needed and I will true up the pattern.