In case you're looking for a bit of embroidery input, my fabulous colleague Alexandra Makin is working on a Bayeux-related project, and her newest update is available on YouTube. She's talking about how to transfer the design in that installation:
This is right on top of my list of things to watch now - I'm very much looking forward to finding out more about how she will handle this!
For my own projects, I've usually traced the design, using a window or a table (depending on how strong the lines on the design original were, and how thick the fabric was) and went at it with my iron gall ink. More rarely I did use the pounce method with charcoal dust and then tracing with ink, and even more rarely I've done freestyle drawing with charcoal, followed by tracing what I was happy with in ink. (Or, extremely rarely because of the small project size, just using the charcoal lines.)
I always find it fascinating to find out more about the original tracings on fabric, and especially to see how much, in many cases, the embroiderers just did as freestyle shading. That, however, is often hard to see, as you usually have either the drawing (when the threads fell out and are lost) or the embroidery (hiding all lines drawn on the fabric)...