I'm progressing with my sampler and am really enjoying it. Rebecca's feedback is comprehensive, helpful and pretty well immediate and I'm learning a whole lot of things I just can't get from books.
Things haven't been going without hitch - my sampler has suffered from a corrugated-like effect caused by too much weft bubbling which I'm gradually getting rid of by watching the amount of weft I put in. I also suffered from a developing hill on the left hand side which can clearly be seen below:
After discounting several possibilities Rebecca thought the most likely cause was uneven beating down of the weft. As I always beat from right to left I may change and try from left to right and with a lighter touch. For the moment though Rebecca suggested trying to ease up the right hand side to even it up and carry on from there. I managed to do this although some of the lower weaving got a bit wobbly but it's a learning curve and the idea of this sampler is to find out how to avoid these sorts of problems. Here is the straightened tapestry: