My list is long. I learned about starch, starch, starch; about color catchers; a lot about threads, fabrics, measurements; added a ton of links to my "favorites" and learned a lot from videos, etc., at those links. I kinda already knew the ins & outs of the scant 1/4" seam, but the details were still educational. It's hard to pick the most important thing. Two days ago, I made a small firm ironing board ... better for applique, bias, etc. than my big thickly padded ironing board ... that was useful info. I learned here. And when I can get to a DIY store and get a thick sheet of styrofoam, I'll surround my Janome 1600 with it, as I learned to do through this QB.