Many thanks for the welcome and your answer to the size question. Someone has suggested that I start out making 9" squares, which is a compromise between the 12" (which I think is too large) and the 6", which is probably too small. I thought I'd pick a size and then try different blocks, possibly ending up with a sampler at some very distant date. I'm trying hard NOT to be overly ambitious at this point. Actually, 8" might be better because more easily divisible....
Snipper74